Polly Robert, Werner Hans-Joachim, Dahle Pål, Taylor Peter R
Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
J Chem Phys. 2006 Jun 21;124(23):234107. doi: 10.1063/1.2202102.
In this work Gaussian-type Geminals (GTGs) are applied in local second-order Moller-Plesset perturbation theory to improve the basis set convergence. Our implementation is based on the weak orthogonality functional of Szalewicz et al., [Chem. Phys. Lett. 91, 169 (1982); J. Chem. Phys. 78, 1420 (1983)] and a newly developed program for calculating the necessary many-electron integrals. The local approximations together with GTGs in the treatment of the correlation energy are introduced and tested. First results for correlation energies of H(2)O, CH(4), CO, C(2)H(2), C(2)H(4), H(2)CO, and N(2)H(4) as well as some reaction and activation energies are presented. More than 97% of the valence-shell correlation energy is recovered using aug-cc-pVDZ basis sets and six GTGs per electron pair. The results are compared with conventional calculations using correlation-consistent basis sets as well as with MP2-R12 results.
在这项工作中，高斯型双原子轨道（GTGs）被应用于局部二阶莫勒-普莱斯特定理微扰理论中，以改善基组收敛性。我们的实现基于萨莱维茨等人的弱正交性泛函[《化学物理快报》91, 169 (1982); 《化学物理杂志》78, 1420 (1983)]以及一个新开发的用于计算所需多电子积分的程序。引入并测试了在处理相关能时局部近似与GTGs相结合的方法。给出了H₂O、CH₄、CO、C₂H₂、C₂H₄、H₂CO和N₂H₄的相关能以及一些反应能和活化能的初步结果。使用aug-cc-pVDZ基组和每个电子对六个GTGs时，价层相关能的恢复率超过97%。将结果与使用相关一致基组的传统计算结果以及MP2-R12结果进行了比较。
