Theoretical ROVibrational Energies (TROVE): A robust numerical approach to the calculation of rovibrational energies for polyatomic molecules
Abstract
We present a new computational method with associated computer program TROVE (Theoretical ROVibrational Energies) to perform variational calculations of rovibrational energies for general polyatomic molecules of arbitrary structure in isolated electronic states. The (approximate) nuclear kinetic energy operator is represented as an expansion in terms of internal coordinates. The main feature of the computational scheme is a numerical construction of the kinetic energy operator, which is an integral part of the computation process. Thus the scheme is selfcontained, i.e., it requires no analytical prederivation of the kinetic energy operator. It is also general, since it can be used in connection with any internal coordinates. The method represents an extension of our model for pyramidal XY _{3} molecules reported previously [S.N. Yurchenko, M. Carvajal, P. Jensen, H. Lin, J.J. Zheng, W. Thiel, Mol. Phys. 103 (2005) 359]. Nonrigid molecules are treated in the HougenBunkerJohns approach [J.T. Hougen, P.R. Bunker, J.W.C. Johns, J. Mol. Spectrosc. 34 (1970) 136]. In this case, the variational calculations employ a numerical finite basis representation for the largeamplitude motion using basis functions that are generated by NumerovCooley integration of the appropriate onedimensional Schrödinger equation.
 Publication:

Journal of Molecular Spectroscopy
 Pub Date:
 October 2007
 DOI:
 10.1016/j.jms.2007.07.009
 Bibcode:
 2007JMoSp.245..126Y