Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
J Chem Phys. 2012 Dec 14;137(22):224509. doi: 10.1063/1.4770293.
Using the van der Waals density functionals (vdW-DFs), we present results of a density functional theory (DFT) study on the structure of layered titanium dichalcogenides TiX(2) (X = S, Se, or Te). By accounting for non-local component in long-ranged electron correlation effects, the vdW-DFs lead to more accurate predictions of the structural parameters relative to conventional DFT. In particular, the vdW-optB86b functional [J. Klimeš et al., Phys. Rev. B 83, 195131 (2011)] gives the most agreement with experimental measurements for the lattice constant involving the vdW interactions. Based on the relaxed structure, the calculated elastic constants and vibrational frequencies are compared to experimental work and overall good agreement is obtained.
利用范德华密度泛函（vdW-DFs），我们对层状二硫属化物 TiX(2)（X = S、Se 或 Te）的结构进行了密度泛函理论（DFT）研究。通过考虑长程电子相关效应中的非局部分量，vdW-DFs 相对于传统 DFT 可以更准确地预测结构参数。特别是，vdW-optB86b 泛函[J. Klimeš 等人，Phys. Rev. B 83, 195131 (2011)]在涉及 vdW 相互作用的晶格常数方面与实验测量结果最为一致。基于弛豫结构，我们将计算出的弹性常数和振动频率与实验工作进行了比较，并且得到了很好的一致性。
