A study of vibrational excitations of HCN in the framework of an algebraic model

作者：Lemus R^*; Sanchez Castellanos M

来源：Molecular Physics, 2011, 109(16): 2009-2023.

DOI：10.1080/00268976.2011.604645

• algebraic description
• bending modes
• su(3) dynamical algebra
• linear molecules
• force constants
• HCN

The vibrational description of the hydrogen cyanide molecule is presented in the framework of the U(2) x U(3) x U(2) algebraic model. In our approach the Hamiltonian is first written in configuration space, and thereafter expressed in an algebraic form by introducing a realization of the coordinates and momenta in terms of the familiar bosonic operators for the harmonic oscillator. An anharmonization procedure is then applied to the algebraic Hamiltonian, which consists in replacing the bosonic operators by a new set of operators belonging to the su(2) algebra for the stretches and the su(3) algebra for the bends. This procedure is equivalent to starting the description in terms of interacting Morse oscillators for the stretching degrees of freedom, without any analog with the bends. This method of obtaining the algebraic representation of the Hamiltonian provides in natural form the connection between the spectroscopic parameters and the structure and force constants. The analysis of the vibrational excitations of HCN is considered, where a description of 73 vibrational levels is carried with a standard deviation of rms 0.91 cm(-1), up to now the best description using an algebraic approach. This fit is used to estimate the potential energy surface.

• 出版日期2011