Artemyev Alexander, Bibikov Anton, Zayets Valentin, Bodrenko Igor
Algodign LLC, Bolshaya Sadovaya 8, Moscow 103001, Russia.
J Chem Phys. 2005 Jul 8;123(2):24103. doi: 10.1063/1.1947193.
Within the resolution of the identity (RI) method, the convergence of the Hartree-Fock (HF) total molecular energy and the multipole moments in the course of the combined regular expansion of the molecular and auxiliary (RI) basis sets is studied. Dunning's cc-pVXZ series is used for both the molecular and the RI basis sets. The results show the calculated quantities converge to the HF limit when both the molecular and the RI basis sets are expanded from correlation-consistent polarized valence double zeta to correlation-consistent polarized valence sextuple zeta. Combinations of molecular/RI basis sets sufficient for convergence of the total energy and of the multipole moments at various accuracy levels have been determined. A measure of the RI basis set incompleteness is suggested and discussed. As it is significantly faster than the standard HF algorithm for small and midsize molecules, the RI-HF method, together with appropriate expanding series of both molecular and RI basis sets, provide an efficient tool to estimate and control the error of the Hartree-Fock calculations due to the finite basis set.
在恒等式分辨（RI）方法中，研究了在分子基组和辅助（RI）基组的联合正则展开过程中，哈特里 - 福克（HF）总分子能量和多极矩的收敛情况。分子基组和RI基组均采用邓宁的cc-pVXZ系列。结果表明，当分子基组和RI基组都从相关一致极化价双ζ扩展到相关一致极化价六重ζ时，计算量收敛到HF极限。已经确定了在各种精度水平下足以使总能量和多极矩收敛的分子/RI基组组合。提出并讨论了一种衡量RI基组不完整性的方法。由于对于中小分子而言，RI - HF方法比标准HF算法快得多，因此RI - HF方法与分子基组和RI基组的适当扩展系列一起，提供了一种有效的工具来估计和控制由于有限基组导致的哈特里 - 福克计算误差。
