First-principles molecular dynamics simulation of liquid

Abstract

The liquid Mg-Bi system exhibits strong compound formation at the 'octet' composition (Mg 3 Bi 2 ). We present results of first-principles molecular dynamics simulations of this alloy system at different compositions: the pure Mg and Bi liquid components, the stoichiometric liquid, and a Mg-rich composition (Mg 62 Bi 28 ). For the pure liquids, our results are in excellent agreement with experimental diffraction data. For Mg 3 Bi 2 , a significant modification of the characteristics of the local ordering is found w.r.t. the crystalline α-phase: the ordering in the liquid is much more ionic. This structural modification is consistent with the structure of the superionic β-phase, that was reported recently by Barnes et al 1994 J. Phys.: Condens. Matter 6 L467. Our simulations cannot reproduce the 'reverse' metal-nonmetal transition observed upon melting, the computed conductivity being much larger than found in experiments. Instead, for the Mg-rich Mg 62 Bi 28 alloy, the calculated conductivity approaches closely to the experimental value.

Studying Static, Dynamic and Transport Properties of Mg3Bi2

“…calculations [9] and these calculations are in good agreement with the Weber experimental data [21]. Both of the simulation results have the initial conguration of liquid structure where density is Mg 3 Bi 2 .…”

“…2. The radial distribution functions of liquid Mg3Bi2 at 1100 K. Solid line represents our MD calculations and dashed line is the rst principles calculations [9].…”

“…Bi ion concentration in magnesium alloys had been studied and their eect on heat resistance had been explained by Yuan et al [7,8]. Solid Mg 3 Bi 2 is a metal and the liquid Mg 3 Bi 2 is a semiconductor so that material has a metalnonmetal transition [9]. These studies have made it more interesting to work on Mg 3 Bi 2 molecule.…”

“…The electronic and structural properties of liquid M g −−Bi alloy are investigated by Guo et al [13]. First principles molecular dynamics simulation of liquid Mg 3 Bi 2 has also been calculated by Wijs [9] and Hao et al [14]. Structural and elastic properties of solid Mg 3 Bi 2 is calculated by Zhou et al [15] and Sedighi et al [16] by rst-principles calculations.…”

High-throughput ab initio analysis of the Bi–In, Bi–Mg, Bi–Sb, In–Mg, In–Sb, and Mg–Sb systems

“…In most cases the experimental results are complemented by thermodynamic modeling [11][12][13]. However, to the best of our knowledge, ab initio studies regarding phase stabilities in these systems are scarce [14][15][16]. To check the completeness of the experimentally known phase diagrams in these systems and provide information on the phase stabilities at low temperatures we have chosen a large library of most common prototypes in binary alloys and calculated ground state energies of these structures with ab initio methods.…”