ETH Zurich, Laboratorium für Physikalische Chemie, Wolfgang-Pauli-Str. 10, CH-8093 Zurich, Switzerland.
J Chem Phys. 2013 May 14;138(18):184105. doi: 10.1063/1.4803693.
We present an efficient algorithm for one- and two-component relativistic exact-decoupling calculations. Spin-orbit coupling is thus taken into account for the evaluation of relativistically transformed (one-electron) Hamiltonian. As the relativistic decoupling transformation has to be evaluated with primitive functions, the construction of the relativistic one-electron Hamiltonian becomes the bottleneck of the whole calculation for large molecules. For the established exact-decoupling protocols, a minimal matrix operation count is established and discussed in detail. Furthermore, we apply our recently developed local DLU scheme [D. Peng and M. Reiher, J. Chem. Phys. 136, 244108 (2012)] to accelerate this step. With our new implementation two-component relativistic density functional calculations can be performed invoking the resolution-of-identity density-fitting approximation and (Abelian as well as non-Abelian) point group symmetry to accelerate both the exact-decoupling and the two-electron part. The capability of our implementation is illustrated at the example of silver clusters with up to 309 atoms, for which the cohesive energy is calculated and extrapolated to the bulk.
我们提出了一种用于单分量和双分量相对论精确解耦计算的有效算法。因此，自旋轨道耦合被用于评估相对论变换后的（单电子）哈密顿量。由于相对论解耦变换必须用原始函数来评估，因此对于大分子来说，相对论单电子哈密顿量的构建成为整个计算的瓶颈。对于已建立的精确解耦协议，我们建立并详细讨论了最小矩阵运算计数。此外，我们应用了我们最近开发的局部 DLU 方案[D. Peng 和 M. Reiher, J. Chem. Phys. 136, 244108 (2012)]来加速这一步骤。通过我们的新实现，可以调用积分密度拟合近似和（阿贝尔和非阿贝尔）点群对称性来执行双分量相对论密度泛函计算，以加速精确解耦和双电子部分。我们的实现能力在高达 309 个原子的银团簇的例子中得到了说明，其中计算了结合能并外推到体相。
