Evolutionary search for new high-k dielectric materials: methodology and applications to hafnia-based oxides

In order to enable computational discovery of novel high-k dielectric materials, we propose a fitness model (energy storage density) that includes the dielectric constant, bandgap, and intrinsic breakdown field. This model, used as a fitness function in conjunction with first-principles calculations and the global optimization evolutionary algorithm USPEX, efficiently leads to practically important results.

Computational materials discovery: the case of the W–B system

Parameter-free variable-compositional evolutionary algorithm searches, together with first-principles calculations, yield the prediction of new tungsten borides, as well as confirmation of a series of experimentally known borides.

Superconductivity of lithium-doped hydrogen under high pressure

Ab initio study of high-pressure electronic and superconductivity properties of lithium-doped hydrogen.

Crystal structure prediction and hydrogen-bond symmetrization of solid hydrazine under high pressure: a first-principles study

Three crystal structures of hydrazine under high pressure have been found, including the reported experimental phase. Pressure-induced hydrogen-bond symmetrization occurs at 235 GPa during the Cc→C2/c transition.

Manipulating topological phase transition by strain

First-principles calculations show that strain-induced topological phase transition is a universal phenomenon in those narrow-gap semiconductors for which the valence band maximum (VBM) and conduction band minimum (CBM) have different parities.

Developing an approach for first-principles catalyst design: application to carbon-capture catalysis

An approach to first-principles catalyst design is presented in which models are used to elucidate geometric–energetic–activity relationships. These design principles are then employed to search structural databases for matching candidate catalysts in the example CO₂ hydration reaction.

1,3,5-Tris(4-bromo­phenyl)benzene prenucleation clusters from meta­dynamics

Recent experimental evidence has shown that the nucleation of 1,3,5-tris(4-bromophenyl)benzene (3BrY) follows a two-step mechanism. In this work, the formation of clusters of 3BrY from homogeneous water and methanol solutions is simulated using metadynamics.

Investigation of real materials with strong electronic correlations by the LDA+DMFT method

A review of the LDA+DMFT method and examples of its applications to real materials with strong electronic correlations, including SrVO₃, V₂O₃, LiV₂O₄, iron pnictide materials, metallic cerium, NiO and MnO.

KNi_0.93Fe^II_0.07Fe^III(PO₄)₂: a new type of structure for a compound of composition M^IM^IIM^III(PO₄)₂

For KNi_0.93Fe^II_0.07Fe^III(PO₄)₂, the partial substitution of Ni by Fe to give a mixed Ni/Fe site is accompanied by the redistribution of K between its original site and a newly populated position.

Bis{2-[(3,5-di­phenyl-1H-pyrrol-2-yl­idene-κN)amino]-3,5-di­phenyl­pyrrol-1-ido-κN}palladium(II): a homoleptic four-coordinate tetra­phenyl­aza­dipyrromethene complex of palladium

The synthesis and single-crystal X-ray structural determination of a homoleptic four-coordinate tetra­phenyl­aza­dipyrromethene complex of palladium are described.

Two novel tri­methyl­sulfonium salts with polymeric {[SbCl₄]⁻}_n or {[CdCl₃]⁻}_n anions

In two organic–inorganic hybrid salts consisting of tri­methyl­sulfonium cations and polymeric {[SbCl₄]⁻}_n or {[CdCl₃]⁻}_n anions, the central metal atoms are coordinated by six Cl atoms, forming an anionic {[SbCl₄]⁻}_n three-dimensional framework or anionic {[CdCl₃]⁻}_n one-dimensional chains.

Anion⋯π inter­actions in copper(I) chloride and bromide coordination polymers bearing 1,4-bis­(pyridazin-4-yl)benzene ligands

The title chloride and bromide coordination polymers are isomorphous and the primary coordination motif consists of cuprohalogenide chains accommodating μ-pyridazine groups. The organic ligands are tetra­dentate and link the inorganic chains into corrugated layers. The packing is influenced by inter­layer anion⋯π inter­actions.

A two-dimensional bilayered Cd^II coordination polymer with a three-dimensional supra­molecular architecture incorporating 1,2-bis­(pyridin-4-yl)ethene and 2,2′-(diazene­diyl)di­benzoic acid

The cadmium complex prepared by reaction of Cd(OAc)₂·2H₂O with 2,2′-(diazene­diyl)di­benzoic acid and 1,2-bis­(pyridin-4-yl)ethene possesses a two-dimensional bilayered structure with a 3⁶4¹³6² topology.

The coordination polymer poly[[aqua(μ-oxalato)[1H-1,2,4-triazole-5(4H)-thione]cadmium(II)] monohydrate]

The title complex is a two-dimensional metal–organic framework, with the Cd^II cation coordinated by three oxalate ligands, a 1H-1,2,4-triazole-5(4H)-thione ligand and a water mol­ecule. The CdO₆S and oxalate units form an extended two-dimensional layered structure.

A tetra­nuclear organotin compound consisting of a core of three fused Sn₂O₂ rings

The title tetranuclear organotin compound has a core of three fused Sn₂O₂ rings. The bulk of the molecule is planar, with the n-butyl and 2-(2-methoxyethoxy)ethyl chains extending perpendicular to the plane.

A novel three-dimensional Zn^II coordination polymer with 1,3,5-tris­(imidazol-1-ylmeth­yl)benzene and cyclo­hexane-1,3,5-tri­carboxyl­ate ligands

In a novel three-dimensional Zn^II coordination polymer with 1,3,5-tris­(imidazol-1-ylmethyl)benzene and cyclo­hexane-1,3,5-tri­carboxyl­ate ligands, there are two types of crystallographically independent Zn^II centres, one in a general position and one on a twofold crystallographic axis.

Poly[tetra­chlorido­{μ₄-tetra­kis­[(imidazol-1-yl)methyl]methane-κ⁴N³:N^3′:N^3′′:N^3′′′}dizinc(II)] exhibiting a three-dimensional diamond topology

The title novel noncentrosymmetric metal–organic framework was prepared solvothermally using the tetra­dentate linker tetra­kis­[(imidazol-1-yl)methyl]methane (tiym) in the presence of zinc nitrate under acidic conditions. With its four peripheral imidazole N atoms, the tiym linkers are bridged by four [ZnCl₂] subunits to generate a three-dimensional diamond topological framework.

A two-dimensional hydrogen-bonded water layer in the structure of a cobalt(III) cubane complex

A cobalt(III) cluster whose Co₄O₄ core has cubane topology crystallizes in a layered structure in which the layer of clusters alternates with a two-dimensional hydrogen-bonded water aggregate with cyclic substructures.

Photochemical dimerization of a fluorinated di­benzyl­ideneacetone in chloro­form solution

(1E,4E)-1,5-Bis(2,6-di­fluoro­phen­yl)penta-1,4-dien-3-one dimerizes under sunlight in chloro­form solution to form the corresponding cyclo­butane derivative. The dimer shows the `truxillic acid'-type arrangement of crystallographic centres of inversion, with cell dimensions closely related to those of the monomer.

A hydrogen-bonded three-component complex: bis­(di­cyclo­hexyl­ammonium) 2,4-di­chloro­phenolate 2,4,6-tri­chloro­phenolate 2,4-di­chloro­phenol

Three different achiral components, dicyclohexylammonium cations, 2,4,6-trichlorophenolate anions and H-atom-bridged 2,4-dichlorophenolate/2,4-dichlorophenol units, are held together by O—H⋯N and O—H⋯O hydrogen bonds to form a chiral hydrogen-bonded pentameric ring. A helical cylinder is established by the packing of the chiral hydrogen-bonded rings along the 4₁ screw axis.

Comparison of N-(3,4,5-tri­meth­oxy­benzyl­idene)naphthalen-1-amine and its reduction product N-(3,4,5-tri­meth­oxy­benzyl)naphthalen-1-amine

N-(3,4,5-Tri­meth­oxy­benzyl­idene)naphthalen-1-amine forms simple hydrogen-bonded sheets built from C—H⋯O hydrogen bonds, linked by π–π stacking inter­actions, and its reduction product forms complex sheets built from N—H⋯O, C—H⋯O and C—H⋯π(arene) hydrogen bonds.

(E)-1-[(5-Chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)methyl­idene]-2-phenyl­hydrazine: sheets built from π-stacked hydrogen-bonded chains

The reaction of a chloro­pyrazole­carbaldehyde with phenyl­hydrazine proceeds via a simple condensation rather than substitution or cyclo­condensation. The resulting compound forms hydrogen-bonded chains, which are linked into sheets by π–π stacking inter­actions.

Four salt phases of theophylline

The monohydrate chloride and bromide salts of theophylline are mutually isostructural, with the cations and anions lying on crystallographic mirror planes (Z′ = ). The BF₄ salt structure is based on planar hydrogen-bonded theopylline cation dimers, with the anions inter­acting with the dimers in a pendant fashion. The anhydrous chloride salt structure has Z′ = 2 and forms one-dimensional chains of cations and anions propagating parallel to the crystallographic c direction.

Supra­molecular association in proton-transfer adducts containing benz­amidinium cations. III. Three mole­cular salts of 3-meth­oxy-, 4-meth­oxy- and 3,4,5-tri­meth­oxy­benzoates with benzamidine

In three benzamidinium–benzoate mol­ecular salts, the amidinium fragments and the carboxyl­ate groups are completely delocalized, and the delocalization favours the aggregation of the mol­ecular components into nonplanar dimers with an (8) graph-set motif by N⁺—H⋯O⁻ (±)(CAHB).

Hirshfeld surface analysis of the 1,1′-(ethane-1,2-diyl)dipyridinium dication in two new salts: perchlorate and peroxo­disulfate

Similar Hirshfeld surface shapes of the 1,1′-(ethane-1,2-diyl)dipyridinium dication are observed in its perchlorate and peroxo­di­sulfate salts. The asymmetric two-dimensional fingerprint plots and the preponderance of H⋯O inter­actions in the crystal structures are discussed.

C—H⋯O and C—H⋯N inter­actions in three hexa­hydro­cyclo­octa­[b]pyridine-3-carbo­nitriles

Three hexahydrocycloocta[b]pyridine-3-carbonitriles differing in the nature of the substituents either at the 2-position of the central pyridine ring or on the pendent aryl ring are presented, demonstrating that changes in the substituents cause significant differences in molecular conformation, intermolecular interactions and packing.

N—H⋯S and N—H⋯O hydrogen bonds: `pure' and `mixed' R²₂(8) patterns in the crystal structures of eight 2-thio­uracil derivatives

The preferred hydrogen-bonding patterns in eight crystal structures of 2-thiouracil derivatives were analysed. In five of the structures, the usual pairs of N—H⋯S or N—H⋯O hydrogen bonds are formed, whereas three structures contain `mixed' R²₂(8) patterns with one N—H⋯S and one N—H⋯O hydrogen bond.