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Computer design of new materials: dream or reality? Computer design of new materials Computer design of new materials.

  1. 1. Computer design New Materials: Dream or Reality? Artem Yoganov (ARO) (1) Department of Geosciences (2) Department of Physics and Astronomy (3) New York Center for Computational Sciences State University of New York, Stony Brook, NY 11794-2100 (4) Moscow State University, Moscow, 119992, RUSSIA.
  2. 2. Trement of matter: Atoms, molecularity guessed that the substance consists of particles: "When he (God) did not create land, no fields or initial dusting of the Universe" (Proverbs, 8:26) (also - Epicur, Lucretia Car , ancient Indians, ...) In 1611, I. Kepler suggested that the structure of iceflows of snowflakes is determined by their atomic structure
  3. 3. Trement of matter: atoms, molecules, crystals 1669 - Birth of crystallography: Nikolay Wagon formulates the first quantitative law of crystallography "Crystallography .. Unproductive, exists only for himself, does not have the consequences ... not anywhere else necessary, she developed inside yourself. It gives reason some limited satisfaction, and its details are so diverse that it can be called inexhaustible; That is why it comes even the best people so chain and so long. "(I.V. Goethe, amateur crystallograph, 1749-1832) Ludwig Boltzman (1844-1906) - the Great Austrian physicist, which built all his theories on atomic ideas. The criticism of an atomism led him to suicide in 1906. In 1912, the hypothesis about the atomic structure of the substance was proved by the experiments of Max von Laue.
  4. 4. The structure is the basis of understanding the properties and behavior of the materials (from http://nobelprize.org) Zins ZNS. One of the first structures solved by Braggs in 1913. Surprise: There are no ZNS molecules in the structure!
  5. 5. X-ray diffraction - the main method of experimental determination of the crystal structure structure diffraction pattern
  6. 6. The ratio of structure and diffraction pattern What will diffract patterns of these "structures"?
  7. 7. Experimental triumphs - the definition of incredibly complex crystalline structurally separated phases of quasicrystalline elements proteins (RB-IV, U.Schwarz'99) The new state of the substance opened in 1982 is found in nature only in 2009! Nobel Prize 2011!
  8. 8. Status of matter Crystalline quasicrystalline amorphous liquid gaseous ("Soft Matter" - polymers, liquid crystals)
  9. 9. Atomic structure - the most main characteristic Substances. Knowing it, you can predict the properties of the material and its electronic structure of the theory of exp. C11 493 482 C22 546 537 C33 470 485 C12 142 144 C13 146 147 C23 160 146 C44 212 204 C55 186 186 186 186 MgSiO3 Perovskite Constants C66 149 147
  10. 10. Several stories 4. Materials of the earth's depth 3. Materials from a computer 2. It is possible to predict crystalline1. About the connection of the structure? Property structures
  11. 11. Why ice is lighter than water? The ice structure contains large empty channels that there is no vied water. Due to these empty channels ice easier ice.
  12. 12. Gas hydrates (clathrates) - ice with filling of molecules (methane, carbon dioxide, chlorine, xenon, etc.) Number of clathral publication Huge deposits of methane hydrate - Hope and save energy? Under low pressure, methane and carbon dioxide form clathrates - 1 liter of the clatarta contains 168 liters of gas! Methane hydrate looks like ice, but burns with water release. CO2 hydrate - form of carbon dioxide burial? Xenon anesthesia mechanism - HE-hydrate formation blocking the transmission of neural signals to the brain (Pauling, 1951)
  13. 13. Microporous materials for the chemical industry and the cleaning of the surrounding media isolates are microporous aluminosilicates, the separation of octane and iso-octane zeolito-chemical. Industry Historical examples of heavy metals poisoning: Qin Shi Juandi Ivan IV Grozny "Neron's disease (37-68) lead (259 - 210 BC) (1530-1584) Mad poisoning: Hats" Aggression, dementia
  14. 14. New and old superconductors phenomenon open in 1911. Challing-onnex the theory of superconductivity - 1957 (Bardeen, Cooper, Schrieffer), but the theory of the most hourly temperature superconductors (Bednorz, Muller, 1986) No! Most powerful magnets (MRI, mass spectrometers, particle accelerators) Magnetic levitation trains (430 km / h)
  15. 15. Surprise: Carbon removable impurity form 1.14 1 TC  EXP [] KB G (E F) V Doped graphite: KC8 (TC \u003d 0.125 K), CAC6 (Tc \u003d 11 K). B-doped diamond: TC \u003d 4 K. Doped fullerenes: RBCS2C60 (TC \u003d 33 K) Molecule molecule structure and appearance Fullerene C60 Fullerite crystals Superconductivity in organic crystals are known since 1979 (Bechgaard, 1979).
  16. 16. As materials can save or destroy at low temperatures, Tin undergoes a phase transition - "tin plague". 1812 - according to legend, the expedition of Napoleon to Russia died due to tin buttons on the uniforms! 1912 - the death of the expedition of Captain R.F. Scott to the Southern Pole, which was attributed to the "tin chum." Transition of the first Rhodasy 13 0c White Tin: 7.37 g / cm3 Gray Tin: 5.77 g / cm3
  17. 17. Alloys with shape memory 1 2 3 4 1- to deformation 3- after heating (20 ° C) (50 ° C) 2- after deformation 4- after cooling (20 ° C) (20 ° C) Example: niti ( Nitinol) Applications: Shunts, dental brackets, elements of oil pipelines and aircraft engines
  18. 18. Wonders optical properties Pleochroism (Cordieritis) - Opening of America and Navigation of the USA UIVADEVOPRELENIE (Calcite) Alexandrite Effect (chrysoberyill) Bowl of Likurg (glass with nanoparticles)
  19. 19. About Nature Colorilla Waves, Å Color Extra Color4100 Purple Lemon-Yellow4300 Indigo Yellow4800 Blue Orange5000 Blue-Green Red5300 Green Purple5600 Lemon-Yellow Purple5800 Yellow Indigo6100 Orange Blue6800 Red Sine-Green
  20. 20. The color depends on the direction (pleochroism). Example: Cordieritis (MG, FE) 2AL4SI5O18.
  21. 21. 2. Prediction of the crystal structures of Oganov A.R., Lyakhov A.O., Valle M. (2011). How Evolutionary Crystal Structure Prediction Works - and Why. ACC. Chem. RES. 44, 227-237.
  22. 22. J. Maddox (Nature, 1988) Task - find the global minimum of the options of energy options. 1 1 1 SEC. Forward all structures impossible: 10 1011 103 Yrs. 20 1025 1017 YRS. 30 1039 1031 YRS. USPEX method overview (Aro & Glass, J.Chem.phys. 2006)
  23. 23. How to find Mount Everest using the kangaroo evolution? (picture from R. Bolegg) We land the landing kangaroo and allow them to multiply (not shown on censorship reasons) .....
  24. 24. How to find a kangaroo evolution to Find Mount Everest? (picture from R. Boles) aaaargh! OUCH .... and from time to time hunters come and remove the kangaroo at smaller altitudes
  25. 25.
  26. 26. Evolutionary calculations "Self-learning" and focus search on the most interesting areas of space
  27. 27. Evolutionary calculations "Self-learning" and focus search on the most interesting areas of space
  28. 28. Evolutionary calculations "Self-learning" and focus search on the most interesting areas of space
  29. 29. Evolutionary calculations "Self-learning" and focus search on the most interesting areas of space
  30. 30. Alternative methods: Random Search (Freeman & Catlow, 1992; Van Eijck & Kroon, 2000; Pickard & Needs, 2006) No "Training" works only for simple Systems (up to 10-12 atoms). Executive annealing (Pannetier 1990; Schön & Jansen 1996) No "Learning" Metadamics (Martonak, Laio, Parrinello 2003) taboo search in the Space Space MINIMA HOPPING (Gödecker 2004) uses the calculation history and " Self learning. " Genetic and Evolutionary Algorithms Bush (1995), Woodley (1999) - not effective method For crystals. Deaven & Ho (1995) is an effective method for nanoparticles.
  31. 31. USPEX (UNIVERSAL STRUCTURE PREDICTOR: Evolutionary Xtallography) (random) Primary population The new generation of structures is made only of the best current structures (1) Heredity (3) Coordinate (2) Mutation lattice mutation (4) Permation
  32. 32. Additional receptions - the parameter of the order of the "fingerprint" structure of the birth of order from chaos in the evolutionary process ["God \u003d Generator of Diversity" © C. Avetisyan] Local order - indicates defective areas
  33. 33. Test: "Who Would Guess That Graphite Is the Stable Allotrope of Carbon AT Ordinary Pressure?" (Maddox, 1988) Three-dimensional SP2 structure, proposed rifle is correctly predicted by R. Hoffmann (1983) as a stable phase at 1 ATM structure with low SP3- Hybridization of energy illustrate SP2-hybridization of carbon chemistry SP hybridization (carbines)
  34. Test: high pressure phases are also reproduced correctly100 GPa: diamond stable 2000 GPa: BC8 Phase stable + found metastable phase, explaining Metastable BC8 Silicon Phase "Superhard Graphite" is known (Kasper, 1964) (Li, Aro, Ma, et al., Prl 2009)
  35. 35. Discovery made with USPEX:
  36. 36. 3. Materials from a computer
  37. 37. Opening of new materials: still experimental method of samples and errors "I did not suffer (ten thousand) failures, but only opened 10000 non-working ways" (TA Edison)
  38. 38. Search for the density substance: Are carbon modifications are possible a dense diamond? Yes, the structure of Almazalmaz has the smallest atomic volume of the greatest incompressibility among all the new structure, elements (and compounds). Tighter diamond! (Zhu, Aro, et al., 2011)
  39. 39. The analogy of the forms of carbon and silica (SiO2) makes it possible to understand the density of new carbon forms. New structures, 1.1-3.2% dense diamond, very high (up to 2.8!) Indicators of refraction and dispersion of light diamond HP3 structure TP12 Structure Ti12 StructureSiO2 Crystobalite SiO2 Quartz SiO2 Kitit Phase SIS2 high pressure
  40. 40.
  41. 41. The hardest oxide - TiO2? (Dubrovinsky et al., Nature 410, 653-654 (2001)) Nishio-Hamane (2010) and Al-Khatatbeh (2009): Compression module ~ 300 GPa, and not 431 GPa. Lyakhov & Aro (2011): Pressure experiments are very complex! Hardness not higher than 16 GPa! TiO2 Softer SiO2 is a washovite (33 GPa), B6O (45 GPa), Al2O3 Corundum (21 GPa).
  42. 42. Are the carbon forms of the harder diamond possible? Not . Material model Li Lyakhov Exp. Hardness, enthalpy, et al. & ARO Structure of GPa EV / Atom (2009) (2011) Almaz 89.7 0.000 Diamond 91.2 89.7 90 Lonsdalet 89.1 0.026 Graphite 57.4 0.17 0.14 C2 / M 84.3 0.163 TiO2 Rutile 12.4 12.3 8-10 I4 / MMM 84.0 0.198 β-Si3N4 23.4 23.4 21 CMCM 83.5 0.282SiO2 Sticks 31.8 30.8 33 P2 / M 83.4 0.166 i212121 82.9 0.784 FMMM 82.2 0.322 CMCM 82.0 0.224 P6522 81.3 0.1211 All solid structures are based on SP3 hybridization Evolutionary calculation
  43. 43. Cold graphite compression gives M-carbon, not a diamond! M-carbon proposed in 2006 in 2010-2012. Tenkalternative structures (W-, R-, S-, Q-, X-, Y-, R-, S-, Q-, X-, Y-, Z-carbon, etc.) M-carbon is confirmed by the new-master experiments M-carbon easier formed from graphite graphite BCT4-carbon graphite M carbon graphite diamond
  44. 44. M-carbon - a new carbon form of Almazgrafite Lonsdaleit Theoretical phase carbon diagram M-carbon-spool carbines
  45. 45. Substance under pressure in Nature P.W. Bridgman 1946 Nobel laureate (physics) 200X store: 100 gp \u003d 1 MBAR \u003d
  46. Neptune has an internal source of heat - but CH4 from where? Uranus and Neptune: H2O: CH4: NH3 \u003d 59: 33: 8. Neptune has an internal source of energy (Hubbard'99). Ross'81 (and Benedetti'99): CH4 \u003d C (diamond) + 2H2. Diamond drop-home source of heat on Neptune? Teoria (Ancilotto'97; Gao'2010) This confirms. Methane hydrocarbon diamond
  47. 47. The harrows is between metals and non-metals and its unique structures are sensitive to B impurities, temperature and pressurealfa-B beta-B T-192
  48. 48. The history of the opening and research of Bora is full of contradictions and detective turns B 1808: J.L.Gay-Lussac and H.Davy announced the opening of a new element - boron.j.l. Gay-Lussac H. Davy 1895: H. Moissan proved that their substances opened no more than 50-60% boron. Moissan material, however, also turned out to be a compound with a boron content of less than 90%. H. Moissan 1858: F. Wöhler described 3 modifications of Bora - "diamond", "graphite-" and "colek-like". All three were connections (for example, ALC12 and B48C2AL). 2007: ~ 16 Crystal modifications were published (most are connections?). It is not known which form is the most stable. F. Wöhler.
  49. 49. Under the pressure of Bohr forms a partially ion structure! B 2004: Chen and Szozhenko: Synthesized a new modification of boron, but could not solve its structure. 2006: Yoganov: determined the structure, proved its stability. 2008: Syboltenko, Kurakvich, Yogan - This phase is one of the most solid known substances (50 GPa hardness). X-ray diffraction. From above - theory, from below - the experimentation structure of the gamma-boron: (B2) Δ + (B12) Δ-, δ \u003d + 0.5 (ARO et al., Nature 2009). Distribution of the most (left) and least (right) stable electrons.
  50. 50. The first phase diagram of Bora - after 200 years of research! Bohr's Flazing Chart (Aro et al., Nature 2009)
  51. 51. Sodium - metal, perfectly described by the model of free electrons
  52. 52. Under the pressure of sodium changes its essence - "Alchemical transformation" Na 1807: Sodium opened Gamphrey Davy. 2002: Hanfland, Syassen, et al. - the first indication on extremely complex chemistry. DAVY sodium under pressure over 1 mbar. Gregornz (2008) - more detailed data. Under the pressure of sodium becomes partially D-metal!
  53. 53. We predicted a new structure that is transparent non-metallo! Sodium becomes transparent at a pressure of ~ 2 mA, EREMETS, ARO et al., Nature 2009) electrons are localized in the "empty place" of the structure, it makes compressed sodium non-metallol
  54. The study of minerals is not only aesthetical formation, but also a virtually the fundamentally important scientific direction of lowering the melting point, the impurities of the Wood is melted at 70 C. Alloy Bi-PB-SN-CD-IN-TL - at 41.5 s!
  55. 64. What is the composition of the inner core of the Earth? The kernel is somewhat less dense than pure iron. In the FE kernel in alloy with light elements, such as S, Si, O, C, H. In FE-C and Fe-H systems, new connections are predicted (FeH4!). Carbon can be contained in the kernel in large quantities [Bazhanov, Yoganov, Gianola, UFN 2012]. Percentage of carbon in the inner core required to explain its density
  56. 65. The nature of the layer D "(2700-2890 km) for a long time remained a mystery" - the root of hot mantlets streams that MgSiO3 is ~ 75 vol.% Of the strangeness of the layer D ": seismic gap, anisotropyvpimatic anisotropy of Corderyite color!
  57. 66. Riddrage - in the existence of a new mineral, MgSiO3 post-pervertoving layer D "(2700-2890 km) Phase diagram D" The MgSiO3 break explains the existence of a layer D "allows you to calculate its temperature explains the variations of the MGSIO3 day of the layer D" grows Perovskitely the cooling of the Earth D "Absent on Mercury and Mars predicted a new family of minerals Decreased - Tschauner (2008)
  58. 67. The structure of the substance is the key to the knowledge of the world. Structures. Definition
  59. 68. Gratitude: My students, graduate students and postaders: a. Lyakhov Y. MA S.E. Boulfelfel C.W. Glass Q. Zhu Y. Xie Colleagues from other laboratories: F. Zhang (PERTH, AUSTRALIA) C. Gatti (U. Milano, Italy) G. Gao (Jilin University, China) A. Bergara (U. Basque Country, Spain) I. Errea (U. Basque Country, Spain) M. Martinez-Canales (UCL, UK) C. Hu (Guilin, China) M. Salvado & P.Pertierra (Oviedo, Spain) V.L. Sybolnko (Paris) D.Yu. Pushchashovsky, V.V. Brazhn (Moscow) Users Users Users (\u003e 1000 people) - http://han.ss.sunysb.edu/~uspex

The essence of the search for the most stable structure is reduced to the calculation of such a state of a substance that has the lowest energy. The energy in this case depends on the electromagnetic interaction of the nuclei and electrons of atoms, of which the crystal studied. It can be estimated with the help of quantum-mechanical calculations based on the simplified Schrödinger equation. So in the USPEX algorithm used theory of density functionalwhich was developed in the second half of the last century. Its main goal is to simplify the calculations of the electronic structure of molecules and crystals. The theory allows you to replace the multielectronic wave function of electronic density, while remaining formally accurate (but in fact the approximation turns out to be inevitable). In practice, this leads to a decrease in the complexity of calculations and, as a result, the time that will be spent on them. Thus, quantum-mechanical calculations are combined with an evolutionary algorithm in USPEX (Fig. 2). How does the evolutionary algorithm work?

It is possible to search for structures with the lowest energy: accidentally position the atoms relative to each other and analyze each such state. But since the number of options is huge (even if atoms are only 10, then the possibilities of their location relative to each other will be about 100 billion), then the calculation would take too much time. Therefore, the success of scientists managed to achieve only after the development of a more cunning method. USPEX algorithm is based on an evolutionary approach (Fig. 2). First, a small number of structures is randomly generated and their energy is calculated. Options with the highest energy, that is, the least stable, the system is removed, and from the most stable generates similar and calculates them. At the same time randomly the computer continues to generate new structures to maintain a diversity of the population, which is an integral condition for successful evolution.

Thus, the problem of predicting crystal structures helped the logic taken from biology. It is difficult to say that there is a gene in this system, because new structures may differ from their predecessors with very different parameters. The most adapted to the selection conditions "individuals" leave offspring, that is, the algorithm, learning to his mistakes, maximizes the chances of success in the next attempt. The system pretty quickly finds a variant with the lowest energy and effectively calculates the situation when the structural unit (cell) contains dozens and even the first hundred atoms, while the previous algorithms could not cope with ten.

One of the new tasks that is placed in front of USPEX in MIPT is the prediction of the tertiary structure of proteins by their amino acid sequence. This problem of modern molecular biology is among the key. In general, before scientists, the task is very difficult also because it is difficult to calculate energy for such a complex molecule as a protein, difficult. According to Artem Oganova, its algorithm is already able to predict the structure of peptides about 40 amino acids.

Video 2. Polymers and biopolymers. What substances relate to polymers? What is the structure of the polymer? How common is the use of polymeric materials? About this says Professor, Phd In Crystallography Artem Oganan.

USPEXA explanation

In one of his scientific and popular artem Oganov (Fig. 3) describes uspex as follows:

"Here is a figurative example for demonstrating a common idea. Imagine that you need to find the highest mountain on the surface of an unknown planet, on which a complete darkness reigns. In order to save resources, it is important to understand that we need not a complete relief map, but only its highest point.

Figure 3. Artem Romaevich Yoganov

You land on the planet a small landing of biorobot, sending them one by one in arbitrary places. The instruction that each robot must perform is to go over the surface against the forces of gravitational attraction and as a result of reaching the tops of the nearest hill, the coordinates of which he must inform the orbital base. We have no funds for a large research contingent, and the likelihood that one of the robots will immediately take the highest mountain, extremely small. Therefore, it is necessary to apply the well-known principle of Russian military science: "Better not by the number, and the ability", implemented herein in the form of an evolutionary approach. The damping of the nearest neighbor, the robots meet and reproduce themselves like this, arranging them along the line between "their" vertices. The offspring of bioreobots proceeds to perform the same instructions: they move towards the elevation of the relief, exploring the region between the two vertices of their "parents". Those "individuals", which came the vertices below the average level, respond (this is being selected) and landing anew randomly (this is simulated maintaining the "genetic diversity" of the population) ".

How to estimate the error with which uspex works? You can take a task with a pre-known correct answer and decide it 100 times with 100 times with the help of the algorithm. If the correct answer is obtained in 99 cases, the probability of the calculation error will be 1%. Typically, the correct predictions are obtained with a probability of 98-99%, when the number of atoms in the elementary cell is 40 pieces.

The USPEX evolutionary algorithm led to many interesting discoveries and even to the development of a new medicinal form of a medical drug, which will be discussed below. I wonder what will be when the new generation supercomputers appear? Will the crystal structural prediction algorithm change? For example, some scientists are engaged in the development of quantum computers. In the future, they will be much more effective than the most advanced modern. According to Artem Oganova, the evolutionary algorithms will leave the leading position, but they will begin to work faster.

Directions of the laboratory: from thermoelectrics to drugs

Uspex turned out to be an algorithm not only efficient, but also multifunctional. At the moment, under the leadership of Artem Oganova, many are conducted scientific work in different directions. Some of the latest projects are attempted simulation of new thermoelectric materials and the prediction of the structure of proteins.

"We have several projects, one of them is the study of low-dimensional materials, such as nanoparticles, material surfaces, Another is the study of chemicals under high pressure. There is another interesting project associated with the prediction of new thermoelectric materials. Now we already know that the adaptation of the method for the prediction of the crystal structures, which we invented, the thermoelectric tasks work efficiently. At the moment, we are ready for a large jerk, the result of which the discovery of new thermoelectric materials should be. It is already clear that the method that we created for thermoelectricians is very powerful, the tests spent are successful. And we are fully prepared to search for new materials. We also deal with the prediction and study of new high-temperature superconductors. We ask the question of predicting the structure of proteins. It is a new task for us and very curious. "

Interestingly, USPEX has already benefited even medicine: "Moreover, we are developing new medications. In particular, we were predicted, a new medicine was obtained and patented, - tells A.R. Yogan. - This is a hydrate 4-aminopyridine, a medicine from multiple sclerosis ".

We are talking about the recently patented laboratory of computer design materials by Valery Rosizen (Fig. 4), Anastasia Naumova and Artem Ogana, allowing symptomatically to treat multiple sclerosis. Patent outdoor, which will help reduce the price of the medicine. Scattered sclerosis is a chronic autoimmune disease, that is, one of those pathologies when its own immune system harms the owner. At the same time, the myelin sheath of nerve fibers is damaged, which normally performs an electrically insulating function. It is very important for the normal operation of neurons: Current on the growing nerve cellsMelinic coated 5-10 times faster than on uncovered. Therefore, multiple sclerosis leads to violations in the work of the nervous system.

The root causes of the occurrence of multiple sclerosis remain completely uncalled. They are trying to understand them in many laboratories in the world. In Russia, this is engaged in the laboratory of biocatalysis at the Institute of Bioorganic Chemistry.

Figure 4. Valery Roizen - one of the authors of a patent for a medicine from sclerosis, Employee of the Laboratory of Computer Design Materials Studies New Drug Forms medical preparations and actively engaged in popularizing science.

Video 3. Scientific and popular lecture Valery Rosizen "Delicious crystals". You will learn about the principles of the work of drugs, about the importance of the form of delivering a medicine into the human body and about the evil twin brother aspirin.

Earlier, 4-aminopyridine in the clinic was already used, but the scientist managed to change chemical composition, improve the absorption of this medication in blood. They obtained the 4-aminopyridine crystal hydrate (Fig. 5) with stoichiometry 1: 5. In this form, the medicine itself was patented and the method of obtaining it. The substance improves the emission of neurotransmitters in neuromuscular synapses, which facilitates the well-being of patients with multiple sclerosis. It is worth noting that such a mechanism implies the treatment of symptoms, but not the very disease itself. In addition to bioavailability, the principal moment in the new development is the following: since it was possible to "conclude" 4-aminopyridine in the crystal, it became more convenient for use in medicine. Crystalline substances are relatively easy to obtain in purified and homogeneous form, and freedom of the drug from potentially harmful impurities is one of the key criteria for a good medication.

Opening of new chemical structures

As mentioned above, USPEX allows you to find new chemical structures. It turns out that even the "habitual" carbon has its own riddles. Carbon is a very interesting chemical element, because it forms an extensive set of structures, ranging from superhard dielectrics, ending with soft semiconductors and even superconductors. To the first one can include diamond and lansdalet, to the second - graphite, to the third - some fullerenes at low temperatures. Despite the wide variety of known carbon forms, scientists under the guidance of Artem Oganova managed to open a fundamentally new structure: it was not previously known that carbon can form complexes in the "Guest-owner" type (Fig. 6). The work took part in the work of the Laboratory of Computer Design of Materials (Fig. 7).

Figure 7. Oleg Fairy, graduate student MFTI, Material computer laboratory officer and one of the authors of the opening new Structure Carbon. In his free time, Oleg is engaged in popularizing science: his articles can be found in the publications "Cat Schredinger", "For Science", Strf.Ru, "Rosatom". In addition, Oleg - Winner of Moscow Science Slam. And the participant of the TV show "The Smart".

The interaction of the "guest-owner" manifests itself, for example, in complexes consisting of molecules that are connected to non-virulent connections. That is, a certain atom / molecule occupies a certain place in the crystal lattice, but it does not forms a covalent connection with the surrounding compounds. Such behavior is widespread among biological molecules that bind to each other, forming durable and large complexes that perform various functions in our organism. In general, due to the compound consisting of two types of structural elements. For substances formed only by carbon, such forms were not known. Scientists have published their discovery in 2014, expanding our knowledge of the properties and behavior of the 14th group chemical elements In general (Fig. 8). It is noted that in the open carbon form covalent bonds There are formed between atoms. We are talking about the type of host-owner comes due to the presence of well-pronounced two types of carbon atoms that have a completely different structural environment.

New high pressure chemistry

In the laboratory of computer design materials are studied which substances will be stable at high pressures. This is how the head of the laboratory argues interest in such research: "We study materials under high pressure, in particular new chemistry, which appears under such conditions. This is a very unusual chemistry that does not fit into the rules of traditional. The knowledge gained on new connections will lead to an understanding of what happens inside the planets. Because these unusual chemical substances Can show themselves as very important materials of planet subsoil. " It is difficult to predict how high-pressure substances behave: most of the chemical rules stop working, because these conditions are very different from usual. Nevertheless, it is necessary to understand this if we want to know how the universe is arranged. The lion's share of the baryon substance of the universe is precisely high pressure inside the planets, stars, satellites. Surprisingly, it is still very few about his chemistry.

New chemistry, which is implemented at high pressure in the Laboratory of Computer Design Materials of MFTI studies PHD (degree similar to Candidate of Science) Gabriele Saleh (Gabriele Saleh):

"I am a chemist, and I am interested in chemistry at high pressures. Why? Because we have the rules of chemistry that have been formulated 100 years ago, but recently it turned out that they cease to work at high pressures. And it is very interesting! Looks like Moon Park: there is a phenomenon that no one can explain; Explore the new phenomenon and try to understand why it is happening - it is very interesting. We started a conversation with fundamental things. But high pressure exists in real world. Of course, not in this room, but inside the earth and on other planets " .

SINCE I'm A Chemist I'm Interested in High-Pressure Chemistry. Why? BECAUSE WERE CHEMICAL RULES WERE WERE ESTABLISHED ONE HUNDRED YEARS AGO But Recently It Was Discovered That These Rules Get Broken At High Pressure. AND IT IS Very Interesting! This Is Like A LoonoPark Because You Have A Phenomenon, Which Nobody Can Rationalize. IT'S Interesting to Study New Phenomenon and To Try to Understand Why Does It Happen. We started from the Fundamental Point of View. But These High Pressures Exist. NOT IN THIS ROOM OF COURSE BUT IN THE INSIDE OF THE EART AND IN OTHER PLANETS.

Figure 9. Coalic acid (H 2 CO 3) is a stable structure under pressure. In the inset from above It is shown that along axes C. Polymer structures are formed. The study of the carbon-oxygen-hydrogen system under high pressures is very important for understanding how the planets are arranged. H 2 O (Water) and CH 4 (methane) are the main components of some giant planets - for example, neptune and uranium, where pressure can reach hundreds of GPa. Large icy satellites (Gamornad, Callisto, Titan) and comets also contain water, methane and carbon dioxide, which is applied to several GPa.

Gabriele told us about her new job, which was recently accepted for publication:

"Sometimes you are engaged in fundamental science, but then detect a direct application of the knowledge gained. For example, we recently sent an article to publish in which we describe the search results for all stable compounds obtained from carbon, hydrogen and oxygen at high pressure. We found one, stable at very low pressures, such as 1 GPa And they were coalic acid H 2 CO 3 (Fig. 9). I studied astrophysics literature and found that the satellites of Ganymed and Callisto [satellites of Jupiter] consist of water and carbon dioxide: from molecules forming coalic acid. So we realized that our discovery suggests education there. coalic acid. This is what I said: It all started with fundamental science and ended with something important for the study of satellites and planets " .

Note that such pressure turn out to be low on those that, in principle, can be found in the universe, but high compared to those that act on us at the surface of the Earth.

So Sometimes You Study Something for Fundamental Science But Then You Discover It Has a Right Application. For example We Have Just Submitted a Paper in Which We Took Carbon, Hydrogen, Oxygen At High Pressure and We Tried to Look for the All Stable Compounds. We Found One Which Was Carbonic Acid and It Was Stable in a Very Low Pressure Like One Gigapascal. I Investigated The Astrophysics Literature and Discovered: There Are Satellites Such As Ganymede or Calisto. ON THERE IS CARBON DIIXIDE AND WATER. The Molecules Which Form This Carbonic Acid. So We Realized That This Discovery Means That ProBably There Would Be Carbonic Acid. This Is What I Mean by Started for Fundamental and Discovering Something Which is Applicable to Planetary Science.

Another example of unusual chemistry, which can be brought regarding well-known cook salt, NaCl. It turns out that if you can create a 350 GPa pressure in your salt, then you will get new connections. In 2013, under the direction of A.R. Oganova was shown that if it was high pressure to NaCl, the unusual compounds will become stable - for example NaCl 7 (Fig. 10) and Na 3 Cl. Interestingly, many of open substances are metals. Gabiel Saleh and Artem Oganov continued pioneer workwhich showed the exotic behavior of sodium chlorides under high pressure and developed a theoretical model that can be used to predict the properties of alkali metal compounds with halogens.

They described the rules that these substances are subject to such unusual conditions. Using the USPEX algorithm, several compounds with formula A 3 Y (A \u003d Li, Na, k; Y \u003d F, CL, BR) were theoretically pressurized to 350 GPa. This led to the discovery of chloride ions in oxidized state -2. "Standard" chemistry prohibits this. In such conditions, new substances may be formed, for example, with the chemical formula Na 4 Cl 3.

Figure 10. Crystal structure of the NaCl conventional salt ( left) and unusual compound NaCl 7 ( on right), stable under pressure.

Chemistry need new rules

Gabriele Saleh (Fig. 11) spoke about his study aimed at a description of the new rules of chemistry, which would have a predictive force not only under standard conditions, but would describe the behavior and properties of substances under high pressure (Fig. 12).

Figure 11. Gabriel Saleh (Gabriele Saleh)

"Two or three years ago, Professor Yoganov discovered that such a simple salt, as NaCl, is not so simple: sodium and chlorine can also form other connections. But no one knew why. Scientists fulfilled the calculations, received results, but remained unknown, why everything happens so, and not otherwise. Since graduate school, I study a chemical connection, and during the study, I managed to formulate some rules, logically explaining what was happening. I studied how electrons behave in such compounds, and came to general laws characteristic of them under high pressure. In order to check whether these rules are the fruit of my imagination or still objectively correctly, I predicted the structure of similar connections - LIBR or NABR and more similar. And indeed - the general rules are followed. If briefly, I saw that there is the following trend: when you apply the pressure to such compounds, then they form the structure of the two-dimensional metal, and then - one-dimensional. Then, under very high pressure, more wild things begin to occur, because chlorine in this case will be the degree of oxidation -2. All chemists know that Chlorine has a degree of oxidation -1, this is a typical example from the textbook: sodium loses the electron, and chlorine takes it. Therefore, oxidative numbers are obtained +1 and -1, respectively. But under high pressure, everything works wrong. We have shown that with the help of some approaches for the analysis of chemical bonds. Also during the work, I was looking for special literature to understand whether anyone was already observed such regularities. And it turned out that yes, observed. If I am not mistaken, sodium bisputat and some other connections are subject to the rules described. Of course, this is just the beginning. When you publish the following works on the topic, we learn whether our model has a real predictive force. Because it is exactly what we are looking for. We want to describe chemical laws that would be respected at high pressures " .

Two Or Three Years Ago Professor Oganov Discovered That The Simple Salt NaCl At High Pressure Is Not Very Simple and Other Compounds Will Form. But Nobody Know Why. They Made A Calculation The Got The Results But You Cannot Say Who This Is Happening. SO SINCE DURING MY PHD I SPECIALIZING IN THE STUDY OF CHEMICAL BONDING, I INVESTIGATED THIS COMPOUNDS AND I FIND SOME RLE TO RATIONALIZE WHAT IS GOING ON. I Investigated How Electrons Behave In This Compounds and Came Up with Some Rules Which This Kinds of Compounds Will Follow At High Pressure. To Check Whether My Rules Were Just My Imagination Or the Were True I Predicted New Structures of Similar Compounds. For example LIBR OR NABE and Some Combinations Like This. And Yes, These Rules Turn Out to Be Followed. In Short, Just Not to Be Very Specialistic, I'Ve Seen That There Is A Tendency: When You Compress Them The Would Form Two-Dimensional Metals, Then One-Dimensional Structure of Metal. And Then at Very High Pressure Some More Wild Would Happen Because The Cl in This Case Will Have the Oxidation Number of -2. All The Lowest Oxidation Number of Cl IS -1, Which Is Typical Textbook Example: Sodium Loses It. SO WE HAVE +1 AND -1 OXIDATION NUMBERS. But At a Very High Pressure It Is Not True Anymore. We demonstrated this with some approaches for chemical bonding analysis. In That Work Also I TriD to Look At The Literature to See If Somebody Have Seen This Kind of Rules Before. And yes, it TURNED OUT THAT THERE WERE SOME. If I'm Not Mistaken, Na-Bi and Other Compounds Turned Out to Follow These Rules. IT IS JUST A Starting Point, of Course. The Other Papers Will Come Up and We Will See Whether This Model Has A Real Predictive Power. Because This Is What We Are Looking For. We Wa Want to Sketch The Chemistry Which Will Work Also for High Pressure.

Figure 12. The structure of the substance with the chemical formula Na 4 Cl 3, which is formed at a pressure of 125-170 GPaIt clearly demonstrates the appearance of a "strange" chemistry under pressure.

If experiment, then selectively

Despite the fact that the USPEX algorithm is characterized by a large predictive force within its tasks, the theory always requires experimental verification. The laboratory of computer design materials is the theoretical, as follows from its name. Therefore, experiments are held in collaboration with other scientific groups. The study strategy adopted in the laboratory, Gabriel Saleh comments as follows:

"We do not conduct experiments - we are theorists. But often we cooperate with people who do it. In fact, I think it is generally difficult. Today, science is narrowly specialized, so it's not easy to find someone who is engaged in both the other " .

WE DON'T Do Experiments, But Often We Collaborate with Some People Who Do Experiments. Actually i Think in Fact It's Hard. Nowadays The Science Is Very Specialized So It's Hard to Find Somebody WHO Does Both.

One of the brightest examples is a prediction of transparent sodium. In 2009 in the journal Nature. The results of work performed under the guidance of Artem Oganova were published. In the article, scientists described the new form of Na, in which it is transparent nonmetal, becoming a dielectric pressure. Why is this happening? This is due to the behavior of valence electrons: under pressure they are displaced in emptiness crystal latticeformed by sodium atoms (Fig. 13). At the same time, the metal properties of the substance disappear and the qualities of the dielectric appear. The pressure of 2 million atmospheres makes sodium red, and 3 million - colorless.

Figure 13. Sodium under pressure is more than 3 million atmospheres. Blue blossom The crystal structure of sodium atoms is shown, orange - bunches of valence electrons in the voids of the structure.

Few people believed that the classic metal could demonstrate such behavior. However, in collaboration with physician Mikhail Eremez, experimental data were obtained that fully confirmed the prediction (Fig. 14).

Figure 14. Photos of the Na sample obtained by combining passing and reflected lighting. Different pressure was applied to the sample: 199 GPa (transparent phase), 156 GPa, 124 GPa and 120 GPa.

It is necessary to work with a light!

Artem Yoganov told us what claims he places to his employees:

"First, they must have a good education. Secondly, being workers. If the man is lazy, then I will not take it to work, and if suddenly I will take it, he will be abused. Several employees who were lazy, inert, amorphous, I just fired. And I think it is absolutely correct and good even for the person himself. Because if a person is not in his place, he will not be happy. He needs to go there, where he will work with a light, with an enthusiasts, with pleasure. And this is good for the laboratory, and good for a person. And those guys who really work beautifully, with a twinkle, the fact that we pay a good salary, they go to the conference, they write articles that then go to the best magazines, they will be fine. Because they are in their place and because the laboratory has good resources in order to support them. That is, the guys do not need to think about the acquisition to survive. They can concentrate on science, on their favorite business, and successfully deal with them. We have now appeared some new grants, and it opens up the opportunity to hire a few more people. Competition is constantly. All year round people submit applications, I take, of course, not all. ". (2016). 4-aminopyridine crystallide, a method of obtaining, a pharmaceutical composition and a method of treatment and / or prevention on its basis. Phys. Chem. Chem. Phys. 18 , 2840–2849;

  • Ma Y., Eremets M., Oganov A.R., Xie Y., Trojan I., Medvedev S. et al. (2009). Transparent Dense Sodium. Nature. 458 , 182–185;
  • Lyakhov A.O., Oganov A.R., Stokes H.T., Zhu Q. (2013). New Developments in Evolutionary Structure Prediction Algorithm USPEX. Comput. Phys. COMMUN. 184 , 1172–1182.

    • - Let's deal with the computer design of new materials. First, what is it? Area Knowledge? When is the idea and this approach?

    - The area is quite new, she is only a few years. By itself, the computer design of new materials was the dream of researchers, technologists, fundamental scientists for many decades. Because the process of opening a new material with the properties you need usually takes many years or even decades of work of whole institutions and laboratories. This is a very expensive process, at the end of which disappointment can wait for you. That is, you are not always able to invent such material. But even when you achieve success, success may require many years of work. This is not suitable at all, we want to invent new materials, new technologies as a rapid way as possible.

    - Can you give an example of such a material that fails or could not be invented?

    - Yes of course. For example, for many decades, people are trying to come up with the material of the harder diamond. There were hundreds of publications on this topic. In some of them, people claimed that the material was found firder diamond, but then inevitably, after some time (usually not very much), these statements were refuted, and it turned out that it was an illusion. Until now, such material is not found, and it is completely clear why. With our methods, we managed to show that it is fundamentally impossible, so there is nothing even to waste time.

    - And if you try to simply explain why it is impossible?

    - Such a property, as a hardness, has a finite limit for each specified material. If we take all the materials that it is possible to take, it turns out that there is a certain global upper limit. It so happened that this upper limit corresponds to diamond. Why diamond? Because in this structure, several conditions are simultaneously satisfied: very strong chemical bonds, a very high density of these chemical bonds, and they are evenly distributed in space. There is not a single direction that would be much harder than another, it is in all directions a very solid. The same graphite, for example, has stronger bonds than diamond, but all these bonds are located in the same plane, and there are very weak connections between the planes, and this weak direction makes the whole crystal soft.

    - How did the method developed and how did scientists try to improve it?

    "The Great Edison said, in my opinion, due to its invention, incandescent bulbs:" I did not suffer ten thousand times in failure, but I only found ten thousand ways that do not work. " This is a traditional style of searching for new materials, which is called Edison in scientific literature. And from this method, of course, people always wanted to move away, because it requires a rare Edison destroyed and Edison patience. And a lot of time, as well as money. This method is not very scientific, it is rather a scientific "tyk". And always, people wanted to move away from this. When computers arose and they began to solve more or less complex tasks, the question immediately arose: "Is it possible all these combinations of various conditions, temperatures, pressures, chemical potentials, chemical composition on a computer instead of doing this in the laboratory?" At first, the hopes were very high. People looked at it a little optimistic and euphoric, but soon all these dreams crashed about everyday life. Those methods that people tried to solve, cannot be achieved in principle.

    - Why?

    - Because the variants of various location of atoms in the structure of the crystal are infinitely many, and each of them will have completely different properties. For example, diamond and graphite is the same substance, and due to the fact that the structure is different, their properties are fundamentally different. So here are various options, different from diamond, and from graphite, there may be indefinitely a lot. What will you start? Where will you stop? How much will it continue? And if you still enter a variable of chemical composition, then different chemical compositions, too, you can also come up with an infinitely much, and the task becomes unbearably difficult. Very quickly, people realized that traditional, standard methods for solving this problem do not lead to absolutely nothing. This pessimism completely buried the first hopes that people cherished, starting from the 60s.

    - Computer design still thinks or, at least, it is felt like a visual thing. I understand that in the 60s, 70s or 80s, this is still a solution is not visual, but mathematical, that is, it is a faster counting, counting.

    - As you understand, when you get numbers on a computer, you can always visualize them, but it's not just that.

    - In general, this is a question only about the readiness of the technique to do.

    - Yes. The numerical account is primed, because from numbers you can always make a picture, and from the picture of the number, probably, too, although not very accurate. There was a number of famous publications since the mid-1980s and ending with the mid-90s, which finally united pessimism in our field. For example, there was a wonderful publication in which it was said that even such simple substancesAs graphite or ice, it is absolutely impossible to predict. Or was an article that was called "predictable crystalline structures", and the first word of this article was "no".

    - What does it mean "predictable whether"?


    - The task of predicting the crystal structure is the kernel of the entire design of new materials. Since the structure defines the properties of the substance, then to predict the substance with the desired properties, you need to predict the composition and structure. The task of predicting the crystal structure can be formulated as follows: Suppose we set the chemical composition, suppose it is fixed, for example, carbon. What will be the most stable carbon form under specified conditions? Under normal conditions, we know the answer - it will be graphite; At high pressures, we also know the answer is diamond. But to create an algorithm that could give you, turns out to be a very difficult task. Or you can formulate the task in a different way. For example, for the same carbon: What is the firm structure that corresponds to this chemical composition? Diamond is obtained. And now let's ask another question: what is the most dense? It seems that also diamond, but no. It turns out that carbon shape is denser the diamond can be invented at least on the computer and it can be synthesized in principle. Moreover, there are many such hypothetical forms.

    - Even so?

    - Even so. But the alignment of the diamond does not come out. Answers to this kind of questions, people learned to receive quite recently. Algorithms recently appeared, programs that can do it appeared. In this case, in fact, the whole area of \u200b\u200bresearch was connected with our 2006 works. After that, many other researchers also began to engage in this task. In general, so far we do not miss the palm of championship and invent more and more new methods, new and new materials.

    - "Who are "we?

    - This is me and my students, graduate students and researchers.

    - In order to be clear, because "we" - it is so multi-valued, in this case the polisantic, it can be perceived differently. And what is revolutionary?

    - The fact is that people realized that this task is associated with an infinitely complex combinatorial problem, that is, the number of options, among which you need to choose the best, infinitely. How can this task solve? Yes, no You can simply not fit and feel comfortable. But we found a way that this task can be solved quite efficiently, a way based on evolution. This can be said, the method of consecutive approximations, when, from initially weak solutions, we arrive at the method of consistent improvement to more and more advanced solutions. It can be said that this is an artificial intelligence method. Artificial intelligence, which makes a number of assumptions, some of them rejected, and from the most believable, most interesting structures and compositions designed even more interesting. That is, he is studying on his own history, because it can be called artificial intelligence.

    - I would like to understand how you invent, invent new materials on some particular example.

    - Let's try to describe it on the example of the same carbon. You want to predict what kind of carbon form most firm. A small number of random carbon structures is given. Some structures will consist of discrete molecules as fullerenes; Some structures will consist of layers as graphite; Some will consist of carbon chains, so-called carbines; Some three-dimensional, kind of diamond (but not only a diamond, such structures are infinitely a lot). You initially generate such structures at first, then you make local optimization, or what we call "relaxation". That is, you move the atoms until the resulting force on the atom does not reset, until all the voltages in the structure disappear until it enters its ideal species or does not get its best local form. And for this structure, you expect properties, such as hardness. We look at the hardness of fullerenes. There are strong connections, but only inside the molecule. The molecules themselves are very weakly connected, thanks to this, the hardness is almost zero. Look at graphite - the same story: strong connections inside the layer, weak between layers, and as a result, the substance is very easily disintegrating, it will be very small. Substances, such as fullerenes or carbins, or graphite, will be very soft, and we immediately reject them. The remaining carbon structures are three-dimensional, strong bonds in all three dimensions, from these structures we choose the most solid and let it be possible to produce subsidiaries. What does it look like? We take one structure, we take another structure, cutting them into pieces, collect them together, as in the designer, and again relax, that is, we give the opportunity to leave all the stresses. There are mutations - this is another way to make offspring from parents. We take one of the most solid structures and mutid it, for example, we apply a huge shift stress so that some connections are simply burst there, and others, new, formed. Or weching atoms in the weakest directions of the structure so that this weakness is removed from the system. All thus produced structures we relax, that is, we remove the internal stresses, and after that we again estimate the properties. It happens that we took a solid structure, mutated it, and it became soft, turned, say, in graphite. We absorb such a structure immediately. And from those who are solid, again produce "children". And so repeat step by step, generation by generation. And quite quickly we come to diamond.

    - At the same time, the moments when we rejected, compare, connect and change the structure, makes artificial intelligence, does the program? Not a human?

    - This makes the program. If we did it, we would be in Kashchenko, because this is a huge number of operations that do not need a person to do and for quite scientific reasons. You understand, a person is born, absorbs the experience from the surrounding world, and with this experience comes a kind of prejudice. We see a symmetric structure - we say: "This is good"; We see asymmetric - say: "This is bad." But for nature sometimes it happens and vice versa. Our method should be free from human subjectivity and prejudice.

    - That's right, I understand what you describe that, in principle, this task is formulated not so much fundamental science as the solution of quite specific tasks set by some regular transnational company? So we need a new cement so that it is more viscous, more dense or, on the contrary, is more liquid and so on.

    - Not at all. In fact, I came from fundamental science in my education, studied after all the fundamental science, not applied. I am now interested in solving applied tasks, especially since the methodology that I invented is applicable for the most important applied tasks of a very wide spectrum. But initially this method was invented to solve fundamental tasks.

    - What kind of?

    - I have been engaged in physics and high pressure chemistry for a long time. This is an area in which many interesting discoveries have been made experimentally. But experiments are complex, and very often experimental results with time turned out to be incorrect. Experiments expensive, labor-intensive.

    - Give an example.

    - For example, for a long time there was a race between Soviet and American scientists: who will receive the first metal hydrogen under pressure. Then it turned out, for example, that many simple elements under pressure become (this is such an alchemical transformation) by transition metal. For example, you take potassium: potassium on the valence sheath is only one s-electron, so under pressure it becomes a D-element; The S-orbital is empty, and the unnecessary D-orbital is settled by this single electron. And this is very important because potassium, becoming a transition metal, then gets the opportunity to enter, for example, in liquid iron. Why is it important? Because now we believe that potassium in small quantities is part of the nucleus of the Earth and is there a source of heat. The fact is that one of potassium isotopes (radioactive potassium-40) is one of the main heat manufacturers on Earth today. If potassium is not included in the Earth's core, then we must fully change our idea of \u200b\u200bthe age of life on Earth, age magnetic field, on the history of the nucleus of the Earth and many other interesting things. Here is the alchemical transformation - s-elements become D-elements. At high pressures when you squeeze the substance, the energy you spend on compression, sooner or later exceeds energy chemical bond and energy of interborbital transitions in atoms. And due to this, you can radically change the electronic structure of the atom and the type of chemical bond in your substance. Complete new types of substances may occur. And the standard chemical intuition in such cases does not work, that is, the rules that we learn from school bench in the lessons of chemistry, they fly to Tartarara, when the pressure reaches quite large quantities. I can tell you what kind of things were predicted using our method and then experimentally proved. When this method appeared, it became for all shock. One of the most interesting works was associated with the sodium element. We predicted that if we sod sodium to pressure of about 2 million atmospheres (by the way, the pressure in the center of the Earth is almost 4 million atmospheres, and you can receive such pressure), it will be no more metal, but a dielectric, moreover, transparent and red colors. When we did this prediction, no one believed. Nature magazine, in which we sent these results, even refused this article to consider, they said that it was impossible to believe it. I contacted experimenters from Mikhail Yeremtsz Group, who also told me that it was impossible to believe in it, but from respect they will still try to carry out such an experiment. And this experiment fully confirmed our predictions. The structure of the new phase of the boron element was predicted - the firm structure for this element, one of the most solid known humanity of substances. And there it turned out that different boron atoms have a different electrical charge, that is, they suddenly become different: some positively, some negatively charged. This article was quoted for almost 200 times for some three years.

    - You said that this is a fundamental task. Or do you decide first of all fundamental tasks and only recently - some practical questions? History with sodium. What for? That is, you sat, sat and thought that I would take - I will take sodium, perhaps, sick him in 2 million atmospheres?

    - Not certainly in that way. I received a grant for studying the behaviors of high-pressure elements in order to better understand the chemistry of elements. Experimental data under high pressure is still very fragmented, and we decided to save more or less the entire periodic table to understand how the elements and their chemistry are changing under pressure. We published a number of articles, in particular, about the nature of superconductivity in oxygen under pressure, because oxygen under pressure becomes a superconductor. For a number of other elements: alkaline elements or alkaline earth elements, and so on. But the most interesting, probably, was the discovery of new phenomena in sodium and in Bore. This, perhaps, there were two elements that surprised us most. So we started. And now we switched to solutions and practical tasks, we cooperate with such companies as Intel, Samsung, Fujitsu, Toyota, Sony. Toyota, as far as I know, with the help of our method recently invented a new material for lithium batteries and is going to produce this material to the market.

    - They took your method, took the search technology of materials, but not you?

    - Yes of course. We do not impose ourselves in the load, and try to help all researchers. Our program is available to all who want to use it. Companies need to pay for the right to use the program. And scientists working in academic science receive it for free, just downloading from our website. Our program has almost 2 thousand users worldwide. And I am very pleased when I see that our users are good to achieve. I have, my group has more than enough of his discoveries, his works, his insights. When we see the same thing in other groups, it just pleases.

    Material is prepared on the basis of the "Postnokuka" radio transmission on the Radio Russian News Service.

    Artem Oganov, one of the most quoted mineralogs of the theoreticals of the world, told us about the computer prediction, which became achievable not so long ago. Previously, this task was not possible to decide because the problem of computer design of new materials includes considered an unresolved problem of crystal structures. But thanks to the efforts of Oganova and his colleagues managed to get closer to this dream and embody her into reality.

    Why this task is important: before, new substances were developed for a very long time and with plenty of effort.

    Artem Oganov: "Experimentors go to the laboratory. Mix various substances at different temperatures and pressures. Receive new substances. Measure their properties. As a rule, these substances do not pose any interest, rejected. And experimenters are trying again to get a little different substance under other conditions, with a slightly different composition. And so step by step, we overcome many failures, spending your life for this years. It turns out that researchers, in the hope of obtaining one material, spend great amount effort, time, as well as money. This process may take years. It can be a dead end and never lead to the opening of the desired material. But even when he leads to success, this success is given by a very expensive price. "

    Therefore, it is necessary to create such a technology that might make error-free predictions. That is, not experimenting in laboratories, but to give the task to the computer to predict what material, with which composition and temperature will have the desired properties under certain conditions. And the computer, turning over numerous options, will be able to answer what kind of chemical composition and which crystal structure will respond to the specified requirements. The result may be such that the desired material does not exist. Or he is not alone.
    And then the second challenge arises, the solution of which is not yet: how to get this material? That is, the chemical composition, the crystal structure is understandable, but there is still no possibility to implement it, for example, on an industrial scale.

    Prediction technology

    The main thing is that it is necessary to predict is a crystal structure. Previously, it was not possible to solve this problem, because there are many options for the location of atoms in space. But the overwhelming part does not represent any interest. These embodiments of atoms in space are important, which are sufficiently stable and have the properties needed for researcher.
    What these properties are: high or low hardness, electrical conductivity and thermal conductivity and so on. The crystal structure is important.

    "If you think, say, about the same carbon, take a look at the diamond and graphite. Chemically this is the same substance. But the properties are completely different. Black super mightmate carbon and transparent super hard diamond, - What determines the difference between them? It is the crystal structure. It is due to her one substance is superhard, the other is super might. One is a conductor of practically metal. Another is a dielectric. "

    In order to learn to predict a new material, you must first learn to predict the crystal structure. For this, Ohanov and his colleagues in 2006, an evolutionary approach was proposed.

    "In this approach, we are not trying to try out all the infinite many crystal structures. We test it step by step, starting with a small random sample, inside which we rank possible solutions, the worst of which we discard. And from the best we produce subsidiaries. Subsidiaries are made by different mutations or by recombinations - by heredity, where we combine various structural features of the composition from two parents. Of this, a subsidiary is a subsidiary, a child chemical composition, a subsidiary. These subsidiaries are also evaluated. For example, in stability or by the chemical or physical property that interests you. And those that were expressed unfavorable, we discard. Those who promising receive the right to produce offspring. We produce a mutation or heredity of the next generation. "

    So step by step, scientists approach the optimal material for them from the point of view of this physical Property. The evolutionary approach in this case works as well as the Darwinian theory of evolution, this principle of Yoganov and its colleagues are carried out on a computer when searching for crystalline structures that are optimal from the point of view of this property or stability.

    "I can also say (but it's already a little on the verge of hooliganism) that when we carried out to work this method (by the way, the development continues. It was improved more and more), we experimented with different ways of evolution. For example, we tried to produce one child from two parents, but from three or four. It turned out that also, as in life, to optimally produce one child from two parents. One child has two parents - Dad and Mom. Not three, not four, not twenty four. This is optimistic both in nature and on the computer. "

    Yoganov patented his method, and now they enjoy almost thousands of researchers around the world and several largest companies, such as Intel, Toyota and Fujitsu. Toyota, for example, according to Oganova, has already invented a new material for lithium batteries that will be used for hybrid cars with the help of this method.

    Diamma problem

    It is believed that the diamond, being a hardness record holder, is the optimal superhard material for all applications. However, this is not the case, because in the gland, for example, it dissolves, and in the oxygen medium high temperatures Lit. In general, the search for the material that would be harder diamond, worried humanity for many decades.

    "A simple computer calculation that was conducted by my group shows that such a material can not be. In fact, the alternate diamond can be only a diamond, but in nano-crystalline form. Other materials to beat the diamond of hardness in the state. "

    Another direction of the Oganova group is the prediction of new dielectric materials that could serve as the basis for super-capacitors for storing electrical energy, as well as for further miniaturization of computer microprocessors.
    "This miniaturization actually meets obstacles. Because the existing dielectric materials are poorly kept electrical charges. There are leakage. And further miniaturization is impossible. If we can get a material that is held on silicon, but at the same time has a much higher dielectric constant than the materials we have, we can solve this task. And we have enough serious promotion also in this direction. "

    And the last thing, which makes Yoganov, is the development of new drugs, that is, too, their prediction. This is possible due to the fact that scientists have learned to predict the structure and chemical composition of the surface of the crystals.

    "The fact is that the surface of the crystal often has a chemical composition differing from the very substance of the crystal. The structure is also very often different. And we found that the surfaces of simple, it would seem inert oxide crystals (such as magnesium oxide) contain very interesting ions (such as ion peroxide). They also contain groups similar to ozone consisting of three oxygen atoms. This explains one extremely interesting and important observation. When a person inhales fine particles of oxide minerals, which seemed to be inert, safe and harmless, these particles play a cruel joke and contribute to the development of lung cancer. In particular, it is known that the carcinogenic substance is asbestos, which is exclusively inert. So, on the surface of this kind of minerals as asbestos and quartz (especially quartz), ions peroxide can be formed, which play a key role in the formation and development of cancer. With the help of our technique, it is also possible to predict the conditions in which the formation of this kind of particles could be avoided. That is, there is hope even to find therapy and warning of lung cancer. In this case, we are talking only about lung cancer. And from a completely unexpected side, the results of our research gave the opportunity to understand, and may even be prevented or healing the lung cancer. "

    If sums up, the prediction of crystalline structures can play a key role in the design of materials for both microelectronics and pharmaceuticals. In general, such a technology opens a new path in the technology of the future, I am sure Yogan.

    You can read about other directions of the Lab Artemia by reference, but to get acquainted with his book Modern Methods of Crystal Structure Prediction