物理化学学报 >> 2012, Vol. 28 >> Issue (08): 1809-1814.doi: 10.3866/PKU.WHXB201205242

热力学,动力学和结构化学 上一篇    下一篇

甲烷晶体的晶格能和弹性性质: 不同方法及泛函的评估

郑朝阳, 赵纪军   

  1. 大连理工大学物理与光电工程学院, 高科技研究院, 辽宁 大连 116024
  • 收稿日期:2012-03-26 修回日期:2012-05-23 发布日期:2012-07-10
  • 通讯作者: 赵纪军 E-mail:zhaojj@dlut.edu.cn
  • 基金资助:

    国家自然科学基金(11174045)和中央高校基本科研业务费(DUT12YQ05)资助项目

Lattice Energies and Elastic Properties of Solid Methane: Assessment of Different Density Functionals

ZHENG Zhao-Yang, ZHAO Ji-Jun   

  1. School of Physics and Optoelectronic Technology, College of Advanced Science and Technology, Dalian University of Technology, Dalian 116024, P. R. China
  • Received:2012-03-26 Revised:2012-05-23 Published:2012-07-10
  • Contact: ZHAO Ji-Jun E-mail:zhaojj@dlut.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (11174045) and Fundamental Research Funds for the Central Universities of China (DUT12YQ05).

摘要:

通过对甲烷晶体进行结构、晶格能和弹性特性的研究, 评估了不包含和包含色散能量修正的密度泛函理论的性能. 我们分别利用不包含色散能量修正的密度泛函理论(DFT) (包含不同的标准泛函和杂化泛函)和包含色散能量修正的密度泛函理论(DFT-D)计算了甲烷晶体特性, 并与实验作对比. 尽管DFT-D 与传统密度泛函理论及杂化密度泛函理论相比, 修正了甲烷晶体中的范德华(vdW)相互作用, 但是一些修正方案过分修正了这种相互作用. 因此, 人们在使用DFT-D方法时务必谨慎.

关键词: 第一性原理, 分子晶体, 范德华相互作用, 晶格能, 甲烷晶体

Abstract:

The performance of density functional theory (DFT) with and without dispersion energy correction for describing van der Waals (vdW) systems is evaluated by calculating the crystal structure, lattice energy, and elastic properties of solid methane. The results obtained from DFT with different exchange-correlation functionals (including some hybrid functionals) and from DFT with dispersion energy correction (DFT-D) methods are compared with experimental values. Although the DFT-D methods typically perform better than the standard and hybrid DFT functionals, some of them overcorrect the vdW interaction in solid methane. Thus, one must be cautious when using DFT-D methods.

Key words: First-principles, Molecular crystal, van der Waals interaction, Lattice energy, Solid methane

MSC2000: 

  • O641