Basis set effects on coupled cluster benchmarks of electronically excited states: CC3, CCSDR(3) and CC2
Basis set effects on coupled cluster benchmarks of electronically excited states: CC3, CCSDR(3) and CC2
复制标题
基组对电子激发态耦合簇基准的影响：CC3、CCSDR(3) 和 CC2
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
W. Thiel
中科院分区：
文献类型：
--
作者：
Mario R Silva;S. Sauer;M. Schreiber;W. Thiel
在CC 2、CCSDR（3）和CC 3计算中，使用增广相关一致的三重zeta aug-cc-pVTZ基组，重新研究了来自先前提出的基准组的28个中等大小分子的垂直电子激发能和单电子性质。结果进行了比较，以前获得的较小的TZVP基组。对于三个耦合集群方法，相关系数大于0.994之间的垂直激发能量计算的两个基组。CC 2和CCSDR（3）结果与CC 3参考值的偏差对于两个基组非常相似，因此证实了先前关于CC 2和CCSDR（3）固有准确度的结论。这种相似性证明了在垂直激发能的CC 3研究中使用基于CC 2或CCSDR（3）的校正来解释基组不完整性的合理性。对于振子强度和激发态偶极矩，使用aug-cc-pVTZ和TZVP基组的CC 2计算分别给出了0.966和0.833的相关系数，这意味着基组收敛较慢。
Vertical electronic excitation energies and one-electron properties of 28 medium-sized molecules from a previously proposed benchmark set are revisited using the augmented correlation-consistent triple-zeta aug-cc-pVTZ basis set in CC2, CCSDR(3), and CC3 calculations. The results are compared to those obtained previously with the smaller TZVP basis set. For each of the three coupled cluster methods, a correlation coefficient greater than 0.994 is found between the vertical excitation energies computed with the two basis sets. The deviations of the CC2 and CCSDR(3) results from the CC3 reference values are very similar for both basis sets, thus confirming previous conclusions on the intrinsic accuracy of CC2 and CCSDR(3). This similarity justifies the use of CC2- or CCSDR(3)-based corrections to account for basis set incompleteness in CC3 studies of vertical excitation energies. For oscillator strengths and excited-state dipole moments, CC2 calculations with the aug-cc-pVTZ and TZVP basis sets give correlation coefficients of 0.966 and 0.833, respectively, implying that basis set convergence is slower for these one-electron properties.