Tran V A, Neese F
Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany.
J Chem Phys. 2020 Aug 7;153(5):054105. doi: 10.1063/5.0013799.
An efficient implementation for calculations of the electronic g-tensor at the level of second-order Møller-Plesset perturbation theory (MP2) is presented. The resolution of identity (RI) approximation is applied for the efficient treatment of two-electron integrals, and gauge including atomic orbitals are used to circumvent the gauge problem present in all magnetic property calculations. Furthermore, given that MP2 is an ingredient in double-hybrid density functional theory (DHDFT), the latter is also featured in the implementation. Calculated g-shifts with RI-MP2 and DHDFT using the double-hybrid density functionals B2PLYP and DSD-PBEP86 are compared to experimental data and published data from other methods including coupled cluster singles doubles. Additionally, the computational performance for medium to large size molecular systems was studied using the RIJK and RIJCOSX approximations for the two-electron integral treatment in the formation of Fock and Fock-like matrices necessary for the calculation of analytic second derivatives.
本文提出了一种在二阶莫勒-普列斯特定则微扰理论（MP2）水平上计算电子g张量的高效实现方法。采用单位分解（RI）近似来有效处理双电子积分，并使用含规范原子轨道来规避所有磁性性质计算中存在的规范问题。此外，鉴于MP2是双杂化密度泛函理论（DHDFT）的一个组成部分，后者也在该实现中有所体现。使用双杂化密度泛函B2PLYP和DSD-PBEP86通过RI-MP2和DHDFT计算得到的g位移与实验数据以及包括耦合簇单双激发在内的其他方法的已发表数据进行了比较。此外，在形成计算解析二阶导数所需的福克矩阵和类福克矩阵时，使用RIJK和RIJCOSX近似进行双电子积分处理，研究了中大型分子体系的计算性能。
