Bozkaya Uğur
Department of Chemistry, Atatürk University , Erzurum 25240, Turkey.
J Chem Theory Comput. 2014 Jun 10;10(6):2371-8. doi: 10.1021/ct500231c.
An efficient implementation of the orbital-optimized second-order perturbation theory with the density-fitting (DF-OMP2) and Cholesky decomposition (CD-OMP2) approaches is presented. The DF-OMP2 method is applied to a set of alkanes, conjugated dienes, and noncovalent interaction complexes to compare the computational cost with the conventional orbital-optimized MP2 (OMP2) [Bozkaya, U.; Turney, J. M.; Yamaguchi, Y.; Schaefer, H. F.; Sherrill, C. D. J. Chem. Phys. 2011, 135, 104103] and the orbital-optimized MP2 with the resolution of the identity approach (OO-RI-MP2) [Neese, F.; Schwabe, T.; Kossmann, S.; Schirmer, B.; Grimme, S. J. Chem. Theory Comput. 2009, 5, 3060-3073]. Our results demonstrate that the DF-OMP2 method provides substantially lower computational costs than OMP2 and OO-RI-MP2. Further application results show that the orbital-optimized methods are very beneficial for the computation of open-shell noncovalent interactions. Considering both computational efficiency and the accuracy of the DF-OMP2 method, we conclude that DF-OMP2 is very promising for the study of weak interactions in open-shell molecular systems.
本文提出了采用密度拟合（DF-OMP2）和Cholesky分解（CD-OMP2）方法对轨道优化二阶微扰理论的高效实现。将DF-OMP2方法应用于一组烷烃、共轭二烯和非共价相互作用复合物，以与传统的轨道优化MP2（OMP2）[Bozkaya, U.; Turney, J. M.; Yamaguchi, Y.; Schaefer, H. F.; Sherrill, C. D. J. Chem. Phys. 2011, 135, 104103]以及采用单位分辨近似的轨道优化MP2（OO-RI-MP2）[Neese, F.; Schwabe, T.; Kossmann, S.; Schirmer, B.; Grimme, S. J. Chem. Theory Comput. 2009, 5, 3060 - 3073]比较计算成本。我们的结果表明，DF-OMP2方法的计算成本比OMP2和OO-RI-MP2低得多。进一步的应用结果表明，轨道优化方法对于开壳非共价相互作用的计算非常有益。综合考虑DF-OMP2方法的计算效率和准确性，我们得出结论，DF-OMP2在研究开壳分子体系中的弱相互作用方面非常有前景。
