Lennard-Jones混合物的有序二元晶体相。

Ordered binary crystal phases of Lennard-Jones mixtures.

作者信息

Fernández Julián R, Harrowell Peter

机构信息

School of Chemistry, University of Sydney, New South Wales 2006, Australia.

出版信息

J Chem Phys. 2004 May 15;120(19):9222-32. doi: 10.1063/1.1689642.

DOI:10.1063/1.1689642

PMID:15267859

Abstract

The lattice energies at zero temperature are calculated, using Lennard-Jones interactions, for a large number of crystal structures associated with ordered binary compounds. In units of the AA interaction length and strength (i.e., sigmaAA= epsilonAA= 1.0) we examine the lowest energy structures, including coexisting phases, across the space of cross-species interactions 0.6< or = sigmaAB< or = 1.1 and 1.0< or = epsilonAB< or = 2.0. The remaining parameters sigmaBB= 0.88 and epsilonBB= 0.5 are chosen so that the parameter space studied includes the space of binary glass-forming alloys. In addition to some large unit cell structures such as Ni3P and PuBr3 appearing among the lowest lattice energies, a number of low-energy structures based on close-packed lattices are found that do not correspond to any experimentally observed crystals. The prevalence and stability of metastable crystal phases at the compositions AB, A2B, and A3B is examined.

摘要

利用 Lennard-Jones 相互作用计算了大量与有序二元化合物相关的晶体结构在零温度下的晶格能。以 AA 相互作用长度和强度为单位（即 σAA = εAA = 1.0），我们研究了跨物种相互作用空间 0.6≤σAB≤1.1 和 1.0≤εAB≤2.0 内的最低能量结构，包括共存相。选择其余参数 σBB = 0.88 和 εBB = 0.5，以便所研究的参数空间包括二元玻璃形成合金的空间。除了一些具有最低晶格能的大晶胞结构（如 Ni3P 和 PuBr3）外，还发现了一些基于密堆积晶格的低能量结构，它们与任何实验观察到的晶体都不对应。研究了在 AB、A2B 和 A3B 组成下亚稳晶相的普遍性和稳定性。