相关论文: Resolving the structure of TiBe$_{12}$

Ab initio phonon calculations for the nonpolar reference structures of the (001), (110), and (111) PbZrO_3/PbTiO_3 [1:1] superlattices are presented. The unstable polar modes in the tetragonal (001) and (110) structures are confined in…

Binary carbides demonstrate attractive set of physical properties that are suitable for numerous and diverse applications. In the present study, we have explored the structural properties, electronic structures, elastic constants, acoustic…

We present a constrained density functional perturbation theory scheme for the calculation of structural and harmonic vibrational properties of insulators in the presence of an excited and thermalized electron-hole plasma. The method is…

A new structure for ${\rm ZnI_2}$ is proposed which it exists in tetragonal state. In this structure the ${\rm ZnI_2}$ molecule exists in a nonlinear array and forms the basis of the tetragonal unit cell with one basis per unit cell. The…

Atomically thin moir\'e materials behave like elastic membranes where at very small twist angles, the van der Waals adhesion energy much exceeds the strain energy. In this ``marginal twist" regime, regions with low adhesion energy expand,…

Flexible mechanical metamaterials possess repeating structural motifs that imbue them with novel, exciting properties including programmability, anomalous elastic moduli and nonlinear and robust response. We address such structures via…

Gibbs free energy models are derived from the calculated electronic and phonon structure of two possible models of $\gamma$-alumina, a defective spinel phase and a hydrogenated spinel phase. The intrinsic vacancies and hydrogen in the two…

Layered, hexagonal crystal structures, like zeta and eta phases, play an important role in ultra-high temperature ceramics, often significantly increasing toughness of carbide composites. Despite their importance open questions remain about…

The structural properties of the CaFe2As2 have been investigated by x-ray and neutron powder diffraction techniques as a function of temperature. Unambiguous experimental evidence is shown for coexistence of tetragonal and orthorhombic…

We report on the ab initio discovery of a novel putative ground state for quasi two-dimensional TiO$_2$ through a structural search using the minima hopping method with an artificial neural network potential. The structure is based on a…

We study the shape, elasticity and fluctuations of the recently predicted (cond-mat/9510172) and subsequently observed (in numerical simulations) (cond-mat/9705059) tubule phase of anisotropic membranes, as well as the phase transitions…

We consider a prototypical dynamical lattice model, namely, the discrete nonlinear Schroedinger equation on nonsquare lattice geometries. We present a systematic classification of the solutions that arise in principal six-lattice-site and…

Tetragonal tungsten bronze (TTB) oxides are one of the most important classes of ferroelectrics. Many of these framework structures undergo ferroelastic transformations related to octahedron tilting deformations. Such tilting deformations…

A panoptic view of architectured planar lattices based on star-polygon tilings was developed. Four star-polygon-based lattice sub-families, formed of systematically arranged triangles, squares, or hexagons, were investigated numerically and…

This study uses the Density Functional Theory to explore the pressure dependent properties of hexagonal BeB2C. The metallic nature of BeB2C was substantiated at ambient pressure, with pressure induced alterations in electronic band…

Recently, hyperbolic lattices that tile the negatively curved hyperbolic plane emerged as a new paradigm of synthetic matter, and their energy levels were characterized by a band structure in a four- (or higher-)dimensional momentum space.…

The phonon dispersion relations and elastic constants for ferromagnetic Ni$_2$MnGa in the cubic and tetragonally distorted Heusler structures are computed using density-functional and density-functional perturbation theory within the…

We have investigated the phonon, elastic and thermodynamic properties of L1$_{2}$ phase Al$_{3}$Ta by density functional theory approach combining with quasi-harmonic approximation model. The results of phonon band structure shows that…

For multi-stage, displacive structural transitions we present a general framework that accounts for various intermediate modulated phases, elastic constant, phonon and related thermodynamic anomalies. Based on the presence or absence of…

Employing ab initio calculations, we discuss chemical, mechanical, and dynamical stability of MoN-TaN solid solutions together with cubic-like MoN/TaN superlattices, as another materials design concept. Hexagonal-type structures based on…