A vibrational CASSCF study of stretch-bend interactions and their influence on infrared intensities in the water molecule
A vibrational CASSCF study of stretch-bend interactions and their influence on infrared intensities in the water molecule
复制标题
拉伸弯曲相互作用的振动 CASSCF 研究及其对水分子红外强度的影响
DOI：
10.1007/bf01125947
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
J. Liévin
中科院分区：
文献类型：
--
作者：
F. Culot;F. Laruelle;J. Liévin
摘要提出了求解振动问题的多构型SCF方法的扩展；它遵循了量子化学中CASSCF方法的哲学。新方法可以更完整地处理非调和模式耦合，收敛速度更快，并且对振动相互作用有更清晰的物理见解。水分子中H2O和D2O同位素体红外跃迁矩的计算说明了这一点。它显示了当振动共振发生时，这种性质如何随波函数的性质而变化。利用这种新的VCASSCF方法进行的详细分析表明，受激弯曲振子对某些纯拉伸跃迁的强度至关重要。
SummaryAn extension of the multiconfigurational SCF approach for the resolution of the vibrational problem is presented; it follows the philosophy of the CASSCF method developed in Quantum Chemistry. The new method allows a more complete treatment of anharmonic mode couplings, converges much faster and gives a clearer physical insight of vibrational interactions. This is exemplified by the calculation of infrared transition moments in the H2O and D2O isotopomers of the water molecule. It is shown how this property varies with the quality of the wave function when vibrational resonances occur. A detailed analysis by means of this new VCASSCF method demonstrates the crucial importance of excited bending oscillators in the intensity of some pure stretching transitions.