The convergence of the electrostatic energy in calculations using periodic boundary conditions is considered context solids and localized aperiodic systems gas condensed phases. Conditions for absolute total are obtained, their implications properties polarized under zero-field assumption discussed. For exact functional obtained. such limit large supercells, where, phase, computational effort proportional to volume. It shown that neutral either or phases, can always be made converge as...

We report on the synthesis of newly discovered cubic phase tin monosulfide π-SnS and compare its properties to well-known monosulfide, α-SnS.

Density Functional Theory (DFT) is one of the most widely used methods for "ab initio" calculations structure atoms, molecules, crystals, surfaces, and their interactions. Unfortunately, customary introduction to DFT often considered too lengthy be included in various curricula. An alternative presented here, drawing on ideas which are well-known from thermodynamics, especially idea switching between different independent variables. The central theme DFT, i.e. notion that it possible...

The ionization potential of small metal and dielectric spheres is considered in different frameworks: classical, semiclassical, quantum mechanical density functional approach. Classical calculations give conflicting results, the generally accepted result for a sphere radius R: WI(R)=bulk work function+(3/8)q2/R shown to be wrong, resulting from classical image too close surface. Using appropriate cutoff potential, function+(1/2)q2/R (previously obtained solvation energy considerations)...

A new nanometric cubic binary phase of the tin mono-selenide system, π-SnSe, was obtained as cube shaped nanoparticles. Its structure and atomic positions were adopted from previously reported π-SnS (P213, a0 = 11.7 Å). The proposed model with 64 atoms per unit cell, refined against experimental X-ray diffraction using Rietveld method (a0 11.9702(9) Å; Rp 1.65 Rwp 2.11). optical properties this SnSe characterized by Raman absorption spectroscopies. band gap assessed to be indirect, Eg 1.28...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemical Hardness in Density Functional TheoryGuy MakovCite this: J. Phys. Chem. 1995, 99, 23, 9337–9339Publication Date (Print):June 1, 1995Publication History Published online1 May 2002Published inissue 1 June 1995https://pubs.acs.org/doi/10.1021/j100023a006https://doi.org/10.1021/j100023a006research-articleACS PublicationsRequest reuse permissionsArticle Views1385Altmetric-Citations114LEARN ABOUT THESE METRICSArticle Views are the...

Brillouin-zone sampling in total-energy calculations of aperiodic systems using periodic boundary conditions is considered. Although the energies converge to exact result limit large supercells for any k-point scheme, they do not at same rate. In particular, it shown that use a single point origin reciprocal space especially inefficient. A scheme proposed, which computationally efficient and its efficacy relative other common approaches demonstrated.

The thermodynamic properties of liquid bismuth have been explored from the melting point to 1100 °C by high-resolution measurements density, heat capacity and static structure factor. These physical display a number anomalies. In particular, we observed evidence for presence temperature-driven liquid-liquid structural transformation that takes place at ambient pressure. latter is characterized density discontinuity occurs 740 °C. Differential thermal analysis revealed endothermal nature this...

The kinematics and kinetics of edge screw dislocations in FCC materials were studied by molecular dynamics, with Cu as a case study. It was found that increasing stress enter into the transonic regime continuously they remain stable up to velocity about 2.2 km s−1. Edge are limited transverse sound at low stresses discontinuously cross higher stresses. For sufficiently long dislocations, subsonic–transonic transition is initiated an athermal nucleation process. Finally, expression for...

The multiple structures presented by the group IV monochalcogenide family of compounds beyond symmetric rock salt structure are commonly ascribed to their stereochemically active lone pairs. Recently, several new, stoichiometrically equivalent, ambient phases SnS and SnSe have been synthesized in addition ground state orthorhombic α-Pnma phase, thus raising question role bonding and, specifically, pairs determining structure. To examine this role, possible, stable mapped density functional...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolvation and Ionization near a Dielectric SurfaceG. Makov A. NitzanCite this: J. Phys. Chem. 1994, 98, 13, 3459–3466Publication Date (Print):March 1, 1994Publication History Published online1 May 2002Published inissue 1 March 1994https://pubs.acs.org/doi/10.1021/j100064a030https://doi.org/10.1021/j100064a030research-articleACS PublicationsRequest reuse permissionsArticle Views358Altmetric-Citations79LEARN ABOUT THESE METRICSArticle Views are the...

A new cubic binary phase was recently discovered in the IV–VI monochalcogenides: tin monosulfide and monose-lenide. Here, we explored possible materials design space for this across groups IV–VI. The structure properties of phase, π including mechanical thermodynamic stability band gap width, were studied using density functional theory monochalcogenide systems interpreted terms a distorted rock-salt structure, bonding between 64 atoms unit cell elucidated. It found that is mechanically...

Abstract Graphullerene is a recently discovered, two-dimensional allotrope of carbon formed from C 60 molecules. It has been synthesized in the form (C Mg 4 ) n and subsequently transformed into by removal atoms. Ab initio calculations are employed to examine structure properties this material. Structurally, graphullerene composed strained Each these molecules connected six neighbors hexagonal network with total eight chemical bonds. We find be meta-stable, owing strain produced covalent...

The origin of the phonon band gap and its controlling factors in low-symmetry crystals are studied monochalcogenide family semiconductors through a combination first-principles calculations introduction quantitative measures bond distortion modes. spectra were calculated for recently discovered 64-atom cubic $\ensuremath{\pi}$-phase monochalcogenides four materials: SnS, SnSe, GeS, GeSe. all these systems exhibit gaps optical spectrum with widths 0.7--2 THz. Raman measurements performed that...

Variational calculation based on a continuum dielectric model, and numerical simulations the RWK2-M water potential pseudopotential for electron–water interaction, are used to evaluate excitation energies optical spectra bound interior states of an excess electron in clusters bulk water. Additionally, data surface obtained from simulations. The simulation approach uses adiabatic dynamics quantum-classical time-dependent self-consistent field (TDSCF) approximation fast-Fourier transform (FFT)...

We describe the unusual properties of γ-SnSe, a new orthorhombic binary phase in tin monoselenide system. This exhibits an ultranarrow band gap under standard pressure and temperature conditions, leading to high conductivity ambient conditions. Density functional calculations identified similarity difference between γ-SnSe conventional α-SnSe based on electron localization function. Very good agreement was obtained for width structure experiment, insight provided mechanism reduction gap. The...

Tin-based monochalcogenides, particularly SnSe and SnS, are of growing interest due to their cost-effectiveness, environmental compatibility, exceptional thermoelectric properties. Beyond the conventional α-Pnma phase, these materials can adopt alternative bulk low-dimensional structures with distinct electronic transport characteristics. The recent experimental discovery a layered γ-Pnma phase in 2023 has further stimulated search for novel structural allotropes within this family...

The dynamic properties of a single dislocation in Cu under an applied stress are studied using constant and temperature molecular dynamics. is found to accelerate terminal velocity. velocity initially increases linearly with finally approaches the shear wave asymptotically. In linear regime drag coefficient determined. results comparable experimental data at high temperatures order magnitude higher low temperatures. width oscillate periodically, period determined by stacking fault energy...

An embedded atom type many-body model for describing rare-gas solids is developed. Model parameters are obtained by fitting zero-temperature compression curves, bulk moduli, and ${C}_{44}$ elastic constants to experimental ab initio data. The then used calculate the pressure-dependent constants, Cauchy discrepancies, melting curves of Ne, Ar, Kr, Xe. It shown that a spherically symmetric cannot reproduce high-pressure properties system. successfully reproduces experimentally observed...

The effect of strain on the microstructure and detailed internal structure dislocation boundaries in pure polycrystalline fcc metals (aluminum, copper, nickel gold) was systematically studied compared as a function following compression at room temperature. At low strains all form cellular structure. dislocations cell walls tend to rearrange themselves from tangles ordered arrays parallel is increased. However rearrangement does not correlate well with stacking fault energy. A good...