Rauhut Guntram, Knizia Gerald, Werner Hans-Joachim
Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
J Chem Phys. 2009 Feb 7;130(5):054105. doi: 10.1063/1.3070236.
The recently proposed explicitly correlated CCSD(T)-F12x (x = a,b) approximations [T. B. Adler, G. Knizia, and H.-J. Werner, J. Chem. Phys. 127, 221106 (2007)] are applied to compute equilibrium structures and harmonic as well as anharmonic vibrational frequencies for H(2)O, HCN, CO(2), CH(2)O, H(2)O(2), C(2)H(2), CH(2)NH, C(2)H(2)O, and the trans-isomer of 1,2-C(2)H(2)F(2). Using aug-cc-pVTZ basis sets, the CCSD(T)-F12a equilibrium geometries and harmonic vibrational frequencies are in very close agreement with CCSD(T)/aug-cc-pV5Z values. The anharmonic frequencies are evaluated using vibrational self-consistent field and vibrational configuration interaction methods based on automatically generated potential energy surfaces. The mean absolute deviation of the CCSD(T)-F12a/aug-cc-pVTZ anharmonic frequencies from experimental values amounts to only 4.0 cm(-1).
最近提出的显式相关CCSD(T)-F12x（x = a,b）近似方法[文献：T. B. Adler, G. Knizia, and H.-J. Werner, J. Chem. Phys. 127, 221106 (2007)]被用于计算H₂O、HCN、CO₂、CH₂O、H₂O₂、C₂H₂、CH₂NH、C₂H₂O以及1,2-C₂H₂F₂反式异构体的平衡结构、简谐振动频率和非谐振动频率。使用aug-cc-pVTZ基组，CCSD(T)-F12a的平衡几何结构和简谐振动频率与CCSD(T)/aug-cc-pV5Z值非常接近。非谐频率通过基于自动生成的势能面的振动自洽场和振动组态相互作用方法进行评估。CCSD(T)-F12a/aug-cc-pVTZ非谐频率与实验值的平均绝对偏差仅为4.0 cm⁻¹。
