Horny Lubos, Paul Ankan, Yamaguchi Yukio, Schaefer Henry F
Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602-2525, USA.
J Chem Phys. 2004 Jul 15;121(3):1412-8. doi: 10.1063/1.1760073.
Highly correlated coupled cluster methods with single and double excitations (CSSD) and CCSD with perturbative triple excitations were used to predict molecular structures and harmonic vibrational frequencies for the electronic ground state X 1Sigma+, and for the 3Delta, 3Sigma+, 3Phi, 1 3Pi, 2 3Pi, 1Sigma+, 1Delta, and 1Pi excited states of NiCO. The X 1Sigma+ ground state's geometry is for the first time compared with the recently determined experimental structure. The adiabatic excitation energies, vertical excitation energies, and dissociation energies of these excited states are predicted. The importance of pi and sigma bonding for the Ni-C bond is discussed based on the structures of excited states.
采用含单双激发的高度相关耦合簇方法（CSSD）以及含微扰三激发的CCSD方法，预测了NiCO电子基态X 1Σ⁺以及3Δ、3Σ⁺、3Φ、1 ³Π、2 ³Π、1Σ⁺、1Δ和1Π激发态的分子结构和谐波振动频率。首次将X 1Σ⁺基态的几何结构与最近确定的实验结构进行了比较。预测了这些激发态的绝热激发能、垂直激发能和解离能。基于激发态的结构，讨论了π键和σ键对Ni-C键的重要性。
