Density-functional theory for vacancies in hard-sphere crystals

被引:19
作者
Groh, B [1 ]
机构
[1] FOM, Inst Atom & Mol Phys, NL-1098 SJ Amsterdam, Netherlands
来源
PHYSICAL REVIEW E | 2000年 / 61卷 / 05期
关键词
D O I
10.1103/PhysRevE.61.5218
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
The equilibrium vacancy concentration in solids can be computed from density-functional theory (DFT) if allowance is made for density profiles with less than one particle per lattice site. For the fundamental-measure theory (FMT), this approach predicts reasonably small vacancy concentrations in hard sphere crystals, in contrast to earlier DFTs. Using an asymptotic analysis of the FMT functional, it is shown that the number of vacancies depends exponentially on the distance to the close packing density, as expected from heuristic arguments. The prefactor of the exponential is calculated for three recently suggested variants of the theory, using density profiles obtained from a quasifree minimization. Extrapolation of the asymptotic behavior to the melting density yields good agreement with other estimates and computer simulation results.
引用
收藏
页码:5218 / 5222
页数:5
相关论文
共 23 条
[21]   APPLICATION OF THE GEOMETRIC GIBBS EQUATION - HARD-SPHERES AT HIGH-DENSITY [J].
SCHAAF, P ;
REISS, H .
JOURNAL OF CHEMICAL PHYSICS, 1990, 92 (02) :1258-1265
[22]   Density functional for hard sphere crystals: A fundamental measure approach [J].
Tarazona, P .
PHYSICAL REVIEW LETTERS, 2000, 84 (04) :694-697
[23]   From zero-dimension cavities to free-energy functionals for hard disks and hard spheres [J].
Tarazona, P ;
Rosenfeld, Y .
PHYSICAL REVIEW E, 1997, 55 (05) :R4873-R4876