Analytical energy gradient of the symmetry-adapted-cluster configuration-interaction general-R method for singlet to septet ground and excited states
Analytical energy gradient of the symmetry-adapted-cluster configuration-interaction general-R method for singlet to septet ground and excited states
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DOI：
10.1063/1.1637033
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发表时间：
2004-02-08
影响因子：
4.4
通讯作者：
Nakatsuji, H
中科院分区：
文献类型：
--
作者：
Ishida, M;Toyota, K;Nakatsuji, H
本文提出并实现了一种利用自适应团簇构型相互作用广义R方法计算单重态和三重态激发态、电离态、电子附着态和高自旋态从四重态到七重态的解析能量梯度的方法。这种方法在研究分子的几何、动力学和态的性质方面是一种强有力的工具，其中不仅涉及单电子过程，而且涉及两电子和多电子过程。本方法的性能得到证实，通过计算的几何形状和光谱常数的双原子和多原子分子在各种电子状态，包括基态和一到三个电子的激发态。得到了平衡几何构型、振动频率和绝热激发能的精确描述，显示了该方法的潜在实用性。特别令人感兴趣的应用是乙炔的C-1（1）A（g）态，CNC的A（2）Delta（u）和B（2）Sigma（u）（+）态以及N-3自由基的B-4（1）和a（4）Pi（u）态. (C)2004年，美国物理学会。
A method of calculating analytical energy gradients of the singlet and triplet excited states, ionized states, electron-attached states, and high-spin states from quartet to septet states by the symmetry-adapted-cluster configuration-interaction general-R method is developed and implemented. This method is a powerful tool in the studies of geometries, dynamics, and properties of the states of molecules in which not only one-electron processes but also two- and multielectron processes are involved. The performance of the present method was confirmed by calculating the geometries and the spectroscopic constants of the diatomic and polyatomic molecules in various electronic states involving the ground state and the one- to three-electron excited states. The accurate descriptions were obtained for the equilibrium geometries, vibrational frequencies, and adiabatic excitation energies, which show the potential usefulness of the present method. The particularly interesting applications were to the C-' (1)A(g) state of acetylene, the A (2)Delta(u) and B (2)Sigma(u)(+) states of CNC and the B-4(1) and a (4)Pi(u) states of N-3 radical. (C) 2004 American Institute of Physics.