Related papers: New Pseudo-Phase Structure for $\alpha$-Pu
We investigate the mixed diamond chain composed of spins 1 and 1/2 when the exchange interaction is alternatingly distorted. Depending on the strengths of frustration and distortion, this system has various ground states. Each ground state…
The structural energetics of PdTi and PtTi have been studied using first-principles density-functional theory with pseudopotentials and a plane-wave basis. We predict that in both materials, the experimentally reported orthorhombic $B19$…
The electronic structures of hexagonal beta-Al9Mn3Si and phi-Al10Mn3 are investigated through self-consistent calculations carried out using the LMTO method. This ab-initio approach is combined with an analysis of a simplified hamiltonian…
We suggest that the commonly-accepted core structure of the 90-degree partial dislocation in Si may not be correct, and propose instead a period-doubled structure. We present LDA, tight-binding, and classical Keating-model calculations, all…
Existing Genetic Algorithms for crystal structure and polymorph prediction can suffer from stagnation during evolution, with a consequent loss of efficiency and accuracy. An improved Genetic Algorithm (GA) is introduced herein which…
Crystalline semiconductors may exist in different polytypic phases with significantly different electronic and optical properties. In this paper, we calculate the electronic structure and optical properties of diamond, Si and Ge in the…
Using ab initio calculations, unexpected structural instability was recently found in the ground state of the U$_2$Mo compound. Instead of the unstable $I4/mmm$ structure, in this work the $P6/mmm$ ($\# 191$) space group, usually called…
The intermetallic $\tau_{11}$ Al$_4$Fe$_{1.7}$Si phase is of interest for high-temperature structural application due to its combination of low density and high strength. We determine the crystal structure of the $\tau_{11}$ phase through a…
The results of electronic structure calculations for a variety of palladium hydrides are presented. The calculations are based on density functional theory and used different local and semilocal approximations. The thermodynamic stability…
In recent computer simulations of a simple monatomic system interacting via the Dzugutov pair potential, freezing of the fluid into an equilibrium dodecagonal quasicrystal has been reported [M. Dzugutov, Phys. Rev. Lett. 70, 2924 (1993)].…
Phase-space electronic structure theory offers up a new and powerful approach for tackling problems with coupled nuclear-electronic dynamics in a fashion that goes beyond Born-Oppenheimer (BO) theory. Whereas BO theory stipulates that we…
We present a theoretical model of the electronic structure of delta-Pu that is consistent with many of the electronic structure related properties of this complex metal. In particular we show that the theory is capable of reproducing the…
Materials with coupled or competing order parameters display highly tunable ground states, where subtle perturbations reveal distinct electronic and magnetic phases. These phases generally are underpinned by complex crystal structures, but…
In this article, we review the analytical and numerical approaches for computing the phase space structures in two degrees-of-freedom Hamiltonian systems that arise in chemical reactions. In particular, these phase space structures are the…
Atomic structures of Al-Co-Cu decagonal quasicrystals (QCs) are investigated using empirical oscillating pair potentials (EOPP) in molecular dynamic (MD) simulations that we enhance by Monte Carlo (MC) swapping of chemical species and…
The existence and properties of phase-space structures in current-carrying pair plasmas is studied by means of the finite amplitude expressions of the pseudo-potential method. Emphasis is given to double layers, solitary structures and…
Materials adopting the diamond structure possess useful properties in atomic and colloidal systems, and are a popular target for synthesis in colloids where a photonic band gap is possible. The desirable photonic properties of the diamond…
The crystal structures and phonon spectra of orthorhombic cadmium titanate with the $Pbnm$ structure and of its two possible ferroelectrically distorted phases with $Pbn2_1$ and $Pb2_1m$ space groups were calculated from first principles…
We investigate the pressure-temperature ($p$-$T$) phase diagram of elemental lithium (Li) up to multiterapascal (TPa) pressures using ab-initio random structure search (AIRSS) and density functional theory (DFT). At zero temperature, beyond…
We study microstructure formation in two nonconvex singularly-perturbed variational problems from materials science, one modeling austenite-martensite interfaces in shape-memory alloys, the other one slip structures in the plastic…