Examination of structural stability and phase transitions in constant-pressure first-principles molecular dynamics simulations
Examination of structural stability and phase transitions in constant-pressure first-principles molecular dynamics simulations
复制标题
恒压第一原理分子动力学模拟中结构稳定性和相变的检验
DOI：
10.1080/08927020290014367
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发表时间：
2002
影响因子：
2.1
通讯作者：
S. Nosé
中科院分区：
文献类型：
--
作者：
T. Morishita;S. Nosé
恒压第一性原理分子动力学（FPMD）模拟是研究晶体结构的有力工具。然而，它需要大量的计算，因此目前还不能对电子态进行高精度的计算。在这份报告中，我们研究了在这种限制下的结构性能的研究中，恒压FPMD的可靠性和适用性。采用晶体硅作为基准来执行恒压FPMD模拟（使用可变形模拟单元）。据发现，在高压（金属）相，结晶对称性与目前的模拟条件被打破。通过压缩和解压缩实现了几种结构转变，但与实验结果不完全一致。我们讨论了这种差异，并得出结论，在布里渊区的k点采样的数量是至关重要的。在目前的计算资源下，建议采用恒压FPMD来探索未知固相的候选结构。
Constant-pressure first-principles molecular dynamics (FPMD) simulation is a powerful tool for investigations of structures in crystals. However, it needs enourmous computations so that highly accurate calculations for electronic states cannot be employed at present. In this report, we examined the reliability and applicability of constant-pressure FPMD in the study of structural properties under this limitation. Crystalline silicon was employed as a benchmark to perform constant-pressure FPMD simulations (with a deformable simulation cell). It is found that, in high pressure (metallic) phases, crystalline symmetry is broken with the present simulation conditions. Several structural transformations were realized by compression and decompression, but they are not entirely consistent with experiment. We discuss this discrepancy and conclude that the number of k point sampling in the Brillouin zone is crucial. It is recommended that constant-pressure FPMD is employed to explore candidate structures for unknown solid phases at present computational resources.