Improved Description of the Orbital Relaxation Effect by Practical Use of the Self-Energy
Improved Description of the Orbital Relaxation Effect by Practical Use of the Self-Energy
复制标题
通过实际使用自能改进轨道弛豫效应的描述
DOI：
10.1002/qua.24625
复制
发表时间：
2014
影响因子：
2.2
通讯作者：
Y. Mochizuki
中科院分区：
文献类型：
--
作者：
M. Saitow;T. Ida;Y. Mochizuki
提出了偏振传播器的轨道弛豫 (OR) 项中完整的二阶自能偏移。与 OR 项中的最佳阻尼参数相结合，改进的传播器产生具有单打和双打 (CCSD) 精度的耦合簇的激励能量。自能转移需要 的浮点运算，其中 N 指分子尺寸的大小。由于二阶偏振传播器需要 的浮点运算，因此构造自能的额外计算量可以忽略不计。显示了包括甘氨酸、2,3,5,6-四氟苯和萘在内的多种分子的数值结果，并且在小于 0.2 eV 的范围内证实了与 CCSD 的结果的良好一致性。还使用 aug-cc-pVNZ (N= D–7) 测试了水分子的基组依赖性，其中这种新开发的方法模拟了 CCSD 值的行为。二阶响应矩阵的自能转移与倾倒参数的使用相结合，可以有效地实现中等尺寸分子系统（包括甘氨酸和萘）的计算。所开发的方法以更实惠的计算费用提供了类似 CCSD 的准确性。 © 2014 Wiley 期刊公司。
The self‐energy shift in the orbital relaxation (OR) term of the polarization propagator complete through the second‐order is presented. In combination with the optimal damping parameter in the OR term, the modified propagator produces the excitation energy of the coupled‐cluster with singles and doubles (CCSD) accuracy. The self‐energy shift requires the floating‐point operation of , whereNrefers to the magnitude of the molecular size. Because the second‐order polarization propagator requires the floating‐point operation of , the additional computational effort to construct the self‐energy is negligibly small. Numerical results are shown for several molecules including glycine, 2,3,5,6‐tetrafluorobenzene, and naphthalene, and promising agreements with those of CCSD are confirmed within less than 0.2 eV. The basis set dependence is also tested for the water molecule using aug‐cc‐pVNZ (N= D–7), where this newly developed approach mimics the behavior of the CCSD values. The self‐energy shifting for the second‐order response matrix in combination with the use of a dumping parameter is efficiently implemented for calculations of medium‐sized molecular systems, including glycine and naphthalene. The developed approach provides CCSD‐like accuracy at a more affordable computational expense. © 2014 Wiley Periodicals, Inc.