An efficient method for energy levels calculation using full symmetry and exact kinetic energy operator: tetrahedral molecules.
An efficient method for energy levels calculation using full symmetry and exact kinetic energy operator: tetrahedral molecules.
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一种使用完全对称性和精确动能算子的能级计算的有效方法：四面体分子。
DOI：
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发表时间：
2015
影响因子：
4.4
通讯作者：
V. Tyuterev
中科院分区：
文献类型：
--
作者：
A. Nikitin;M. Rey;V. Tyuterev
同时使用完整的分子对称性和精确的动能算符(KEO)对于准确预测从势能面(PES)的高能范围内的振动能级是至关重要的。一种允许变分计算快速收敛的有效方法将允许使用实验数据迭代优化PES参数。在这项工作中，我们提出了一种适用于四面体AB4分子的方法，对于这些分子来说，高对称性的使用对于振动计算是至关重要的。给出了六个冗余角的对称性自适应压缩角基集合。给出了用该基组显式计算KEO和PES角矩阵元的简单公式。导出了无SIN(Q)(-2)型奇点的振动KEO的对称形式(六个冗余角)。振动矩阵元的计算采用基于张量形式的高效递推算法。证明了计算CH4分子振动能级具有良好的基组收敛特性。
A simultaneous use of the full molecular symmetry and of an exact kinetic energy operator (KEO) is of key importance for accurate predictions of vibrational levels at a high energy range from a potential energy surface (PES). An efficient method that permits a fast convergence of variational calculations would allow iterative optimization of the PES parameters using experimental data. In this work, we propose such a method applied to tetrahedral AB4 molecules for which a use of high symmetry is crucial for vibrational calculations. A symmetry-adapted contracted angular basis set for six redundant angles is introduced. Simple formulas using this basis set for explicit calculation of the angular matrix elements of KEO and PES are reported. The symmetric form (six redundant angles) of vibrational KEO without the sin(q)(-2) type singularity is derived. The efficient recursive algorithm based on the tensorial formalism is used for the calculation of vibrational matrix elements. A good basis set convergence for the calculations of vibrational levels of the CH4 molecule is demonstrated.
DOI：
10.1016/j.jqsrt.2011.06.004
发表时间：
2011-10-01
影响因子：
2.3
作者：
Jacquinet-Husson, N.;Crepeau, L.;Vander Auwera, J.
通讯作者：
Vander Auwera, J.