Ex nihilo crystal structure discovery
Lead Research Organisation:
University College London
Department Name: Physics and Astronomy
Abstract
The discovery that matter is made up of atoms ranks as one ofmankind's greatest achievements. Twenty first century science isdominated by a quest for the mastery (both in terms of control andunderstanding) of our environment at the atomic level.In biology, understanding life (preserving it, or even attempting tocreate it) revolves around large, complex, molecules -- RNA, DNA, andproteins.Global warming is dictated by the particular way atoms are arrangedto make small greenhouse gas molecules, carbon dioxide and so on.The drive for faster, more efficient, cheaper computer chips forcesnanotechnology upon us. As the transistors that make up themicroscopic circuits are packed ever closer together, electronicengineers must understand where the atoms are placed, or misplaced, inthe semiconducting and insulating materials.Astronomers are currently, daily, discovering new planets outside oursolar system, orbiting alien stars. The largest are the easiest tospot, and many are far larger than Jupiter. The more massive theplanet the higher pressures endured by the matter that makes up itsbulk. How can we hope to determine the structure of matter at theseconditions?The atomic theory of matter leads to quantum mechanics -- a mechanicsof the every small. In principle, to understand and predict thebehaviour of matter at the atomic scale simply requires the solutionof the quantum mechanical Schroedinger equations. This is a challengein itself, but in an approximate way it is now possible to quicklycompute the energies and properties of fairly large collections ofatoms. But is it possible to predict how those atoms will be arrangedin Nature - ex nihilo, from nothing but our understanding ofphysics?Some have referred to it as a scandal that the physical sciencescannot routinely predict the structure of even simple crystals -- butmost have assumed it to be a very difficult problem. A minimum energymust be found in a many dimensional space of all the possiblestructures. Those researchers brave enough to tackle this challengehave done so by reaching for complex algorithms -- such as geneticalgorithms, which appeal to evolution to breed ever betterstructures (with better taken to mean more stable). However, Ihave discovered to my surprise, and to others', that the very simplestalgorithm -- throw the collection of atoms into a box, and move theatoms downhill on the energy landscape -- is remarkably effectiveif it is repeated many times.This approach needs no prior knowledge of chemistry. Indeed thescientist is taught chemistry by its results -- this is critical ifthe method is to be used to predict the behaviour of matter underextreme conditions, where learned intuition will typically fail.I have used this approach, which I call random structure searching to predict the structure of crystals ex nihilo. My firstapplication of it has been to silane at very high pressures, and thestructure I predicted has recently been seen in experiments. Butprobably the most impressive application so far has been to predictingthe structure of hydrogen at the huge pressures found in the gas giantplanets, where it may be a room temperature superconductor.In the course of my fellowship I will extend this work to try toanticipate the structure of matter in the newly discovered exoplanets,to try to discover and design materials with extreme (and hopefully,extremely useful) properties, and to help pharmaceutical researchersunderstand the many forms that their drug molecules adopt when theycrystallise.
Organisations
People |
ORCID iD |
Christopher Pickard (Principal Investigator) |
Publications
Ahnert S
(2017)
Revealing and exploiting hierarchical material structure through complex atomic networks
in npj Computational Materials
Bardwell DA
(2011)
Towards crystal structure prediction of complex organic compounds--a report on the fifth blind test.
in Acta crystallographica. Section B, Structural science
Bonhomme C
(2010)
New perspectives in the PAW/GIPAW approach: J(P-O-Si) coupling constants, antisymmetric parts of shift tensors and NQR predictions.
in Magnetic resonance in chemistry : MRC
Bonhomme C
(2012)
First-principles calculation of NMR parameters using the gauge including projector augmented wave method: a chemist's point of view.
in Chemical reviews
Bradley JP
(2012)
Probing intermolecular hydrogen bonding in sibenadet hydrochloride polymorphs by high-resolution (1) H double-quantum solid-state NMR spectroscopy.
in Journal of pharmaceutical sciences
Cadars S
(2009)
Characterizing slight structural disorder in solids by combined solid-state NMR and first principles calculations.
in The journal of physical chemistry. A
Chandran CV
(2010)
Improving sensitivity and resolution of MQMAS spectra: a 45Sc-NMR case study of scandium sulphate pentahydrate.
in Journal of magnetic resonance (San Diego, Calif. : 1997)
Chen J
(2017)
Double-layer ice from first principles
in Physical Review B
Chen J
(2013)
Quantum simulation of low-temperature metallic liquid hydrogen.
in Nature communications
Chen J
(2016)
Two Dimensional Ice from First Principles: Structures and Phase Transitions.
in Physical review letters
Cuny J
(2009)
Density functional theory calculations of 95Mo NMR parameters in solid-state compounds.
in Chemphyschem : a European journal of chemical physics and physical chemistry
Cuny J
(2011)
95Mo nuclear magnetic resonance parameters of molybdenum hexacarbonyl from density functional theory: appraisal of computational and geometrical parameters.
in Physical chemistry chemical physics : PCCP
Cuny J
(2013)
95Mo solid-state nuclear magnetic resonance spectroscopy and quantum simulations: synergetic tools for the study of molybdenum cluster materials.
in Inorganic chemistry
Davies E
(2014)
Citrate bridges between mineral platelets in bone
in Proceedings of the National Academy of Sciences
De Gortari I
(2010)
Time averaging of NMR chemical shifts in the MLF peptide in the solid state.
in Journal of the American Chemical Society
Drummond ND
(2011)
Quantum Monte Carlo study of a positron in an electron gas.
in Physical review letters
Dumez JN
(2009)
Calculation of NMR chemical shifts in organic solids: accounting for motional effects.
in The Journal of chemical physics
Errea I
(2015)
High-pressure hydrogen sulfide from first principles: a strongly anharmonic phonon-mediated superconductor.
in Physical review letters
Fortes AD
(2009)
Equation of state and phase transition of deuterated ammonia monohydrate (ND3.D2O) measured by high-resolution neutron powder diffraction up to 500 MPa.
in The Journal of chemical physics
Fortes AD
(2009)
Crystal structure of ammonia monohydrate phase II.
in Journal of the American Chemical Society
Früchtl HA
(2009)
The structure of (SCN)(x): a study using molecular and solid-state density functional theory calculations.
in Chemistry (Weinheim an der Bergstrasse, Germany)
Gao H
(2019)
Prediction of pressure-induced stabilization of noble-gas-atom compounds with alkali oxides and alkali sulfides
in Physical Review Materials
Gao H
(2020)
Coexistence of plastic and partially diffusive phases in a helium-methane compound.
in National science review
Gao SP
(2009)
Core-level spectroscopy calculation and the plane wave pseudopotential method.
in Journal of physics. Condensed matter : an Institute of Physics journal
Goncharov AF
(2015)
Backbone NxH compounds at high pressures.
in The Journal of chemical physics
Goto Y
(2017)
Pressure-Stabilized Cubic Perovskite Oxyhydride BaScO2H.
in Inorganic chemistry
Griffiths GI
(2012)
High pressure ionic and molecular crystals of ammonia monohydrate within density functional theory.
in The Journal of chemical physics
Griffiths GI
(2012)
Crystal structure of ammonia dihydrate II.
in The Journal of chemical physics
Hasnip P
(2014)
Density functional theory in the solid state
in Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
Hassanali AA
(2012)
The fuzzy quantum proton in the hydrogen chloride hydrates.
in Journal of the American Chemical Society
Hung I
(2009)
Probing heteronuclear (15)N-(17)O and (13)C-(17)O connectivities and proximities by solid-state NMR spectroscopy.
in Journal of the American Chemical Society
Ivanov AS
(2012)
Inorganic double-helix structures of unusually simple lithium-phosphorus species.
in Angewandte Chemie (International ed. in English)
Jung H
(2015)
Elucidation of the Local and Long-Range Structural Changes that Occur in Germanium Anodes in Lithium-Ion Batteries
in Chemistry of Materials
Kim DY
(2011)
Predicted formation of superconducting platinum-hydride crystals under pressure in the presence of molecular hydrogen.
in Physical review letters
Köster TK
(2011)
Resolving the different silicon clusters in Li12Si7 by 29Si and (6,7)Li solid-state NMR spectroscopy.
in Angewandte Chemie (International ed. in English)
Li XZ
(2013)
Classical and quantum ordering of protons in cold solid hydrogen under megabar pressures.
in Journal of physics. Condensed matter : an Institute of Physics journal
Li Y
(2015)
Metallic icosahedron phase of sodium at terapascal pressures.
in Physical review letters
Li Y
(2016)
Dissociation products and structures of solid H 2 S at strong compression
in Physical Review B
Liu C
(2020)
Plastic and Superionic Helium Ammonia Compounds under High Pressure and High Temperature
in Physical Review X
Lyle MJ
(2015)
Prediction of 10-fold coordinated TiO2 and SiO2 structures at multimegabar pressures.
in Proceedings of the National Academy of Sciences of the United States of America
Marqués M
(2011)
Crystal structures of dense lithium: a metal-semiconductor-metal transition.
in Physical review letters
Martinez-Canales M
(2012)
Thermodynamically stable phases of carbon at multiterapascal pressures.
in Physical review letters
Martinez-Canales M
(2017)
Dirac cones in two-dimensional borane
in Physical Review B
Martinez-Canales M
(2017)
Dirac cones in Two-dimensional Borane
Mayo M
(2016)
Ab Initio Study of Phosphorus Anodes for Lithium- and Sodium-Ion Batteries
in Chemistry of Materials
Middlemiss DS
(2010)
Solid-state NMR calculations for metal oxides and gallates: shielding and quadrupolar parameters for perovskites and related phases.
in Journal of magnetic resonance (San Diego, Calif. : 1997)
Mitchell MR
(2011)
(119)Sn MAS NMR and first-principles calculations for the investigation of disorder in stannate pyrochlores.
in Physical chemistry chemical physics : PCCP
Description | The Ab initio random structure searching (AIRSS) approach to material structure prediction was developed over the period of the leadership fellowship. It is now recognised as a key tool for computational materials discovery, complementing "materials genome" type database approaches. AIRSS has been applied to a very wide range of systems: battery anode materials, pharmaceutical compounds, complex defects, and interfaces. The major scientific discoveries have been in the field of high pressure physics. I computationally identified a new route to elemental magnetism (in dense potassium), and a what others have called a "new paradigm" of ultradense matter. I found that structure is complex at extremely high (terapascal) pressures of the sort encountered in laser shock experiments such as performed at the National Ignition Facility (LLNL, USA). Aluminium was found to adopt a incommensurate host-guest phase, four new thermodynamically stable of carbon were discovered, and the end of water (its decomposition) proposed. AIRSS, along with my earlier GIPAW theory, of solid state NMR, is playing a key role in the development of NMR Crystallography. |
Exploitation Route | It is likely that AIRSS, or methods inspired by it, will be implemented in commercial scientific software packages in due course. In 2017 the AIRSS package was released under GPL2. |
Sectors | Aerospace, Defence and Marine,Agriculture, Food and Drink,Chemicals,Construction,Electronics,Energy,Environment,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology,Security and Diplomacy,Transport |
URL | https://www.mtg.msm.cam.ac.uk/Codes/AIRSS |
Title | AIRSS |
Description | Ab initio Random Structure Searching (AIRSS) is a very simple, yet powerful and highly parallel, approach to structure prediction. The concept was introduced in 2006 and its philosophy more extensively discussed in 2011. Random structures - or more precisely, random "sensible" structures - are generated and then relaxed to nearby local energy minima. Particular success has been found using density functional theory (DFT) for the energies, hence the focus on "ab initio" random structure searching. The sensible random structures are constructed so that they have reasonable densities, and atomic separations. Additionally they may embody crystallographic, chemical or prior experimental/computational knowledge. Beyond these explicit constraints the emphasis is on a broad, uniform, sampling of structure space. AIRSS has been used in a number of landmark studies in structure prediction, from the structure of SiH4 under pressure to providing the theoretical structures which are used to understand dense hydrogen (and anticipating the mixed Phase IV), incommensurate phases in aluminium under terapascal pressures, and ionic phases of ammonia. The approach naturally extends to the prediction clusters/molecules, defects in solids, interfaces and surfaces (interfaces with vacuum). The AIRSS package is tightly integrated with the CASTEP first principles total energy code. However, it is relatively straightforward to modify the scripts to use alternative codes to obtain the core functionality, and examples are provided. The AIRSS package is released under the GPL2 licence. |
Type Of Technology | Software |
Year Produced | 2017 |
Impact | It appears that researcher are routinely using AIRSS. |
URL | https://www.mtg.msm.cam.ac.uk/Codes/AIRSS |