用于大规模双组分相对论计算的局域幺正变换方法：单电子狄拉克哈密顿量的情形。

Local unitary transformation method for large-scale two-component relativistic calculations: case for a one-electron Dirac Hamiltonian.

机构信息

Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.

出版信息

J Chem Phys. 2012 Jun 28;136(24):244102. doi: 10.1063/1.4729463.

DOI:10.1063/1.4729463

PMID:22755560

Abstract

An accurate and efficient scheme for two-component relativistic calculations at the spin-free infinite-order Douglas-Kroll-Hess (IODKH) level is presented. The present scheme, termed local unitary transformation (LUT), is based on the locality of the relativistic effect. Numerical assessments of the LUT scheme were performed in diatomic molecules such as HX and X(2) (X = F, Cl, Br, I, and At) and hydrogen halide clusters, (HX)(n) (X = F, Cl, Br, and I). Total energies obtained by the LUT method agree well with conventional IODKH results. The computational costs of the LUT method are drastically lower than those of conventional methods since in the former there is linear-scaling with respect to the system size and a small prefactor.

摘要

提出了一种在无自旋无限阶道格拉斯-克劳斯-赫斯（IODKH）水平下进行双组分相对论计算的精确高效方案。该方案称为局部幺正变换（LUT），基于相对论效应的局域性。在 HF、HCl、HBr、HI 和 At 等双原子分子以及 HX(n)（X = F、Cl、Br 和 I）卤化氢团簇中，对 LUT 方案进行了数值评估。LUT 方法得到的总能量与传统 IODKH 结果吻合良好。由于前者的计算成本与系统大小呈线性关系，并且系数较小，因此 LUT 方法的计算成本大大低于传统方法。