New Variational Method for the Ab Initio Study in Valence Coordinates of the Renner−Teller Effect in Tetra-Atomic Systems

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• 作者：Laurent Jutier ; Cline Lonard
• 刊名：Journal of Chemical Theory and Computation
• 出版年：2010
• 出版时间：May 11, 2010
• 年：2010
• 卷：6
• 期：5
• 页码：1565-1579
• 全文大小：468K
• 年卷期：v.6,no.5(May 11, 2010)
• ISSN：1549-9626

文摘

A new variational methodology for the treatment of the Renner−Teller effect in tetra-atomic molecules has been developed in valence coordinates. The kinetic-energy operator of Bramley et al. [Mol. Phys. 1991, 73, 1183] for any sequentially bonded four-atom molecule, A−B−C−D, in the singlet nondegenerate electronic state has been adapted to the Renner−Teller and spin couplings by modifying the expression of the nuclear angular momentum. The total Schrdinger equation is solved by diagonalizing the Hamiltonian matrix in a three-step contraction scheme. The main advantage of this new theoretical development is the possibility of studying different isotopomers using the same potential-energy surfaces. This procedure has been tested on HCCH⁺ and its deuterated derivatives DCCD⁺ and DCCH⁺. The calculated rovibronic band origins were compared with previous data deduced from the Jacobi coordinates methodology, dimensionality reduced variational treatment, and photoelectron spectra with a good global agreement. Rotational structures for these systems are also tackled.