Computational Chemistry and Molecular Modeling
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
The problem of the computation of the Centrifugal Distortion Constants (CDC) related to a diatomic potential is considered. The analytical expressions obtained from a reformulation of the Rayleigh-Schrödinger perturbation theory are used [Kobeissi et al., J. Mol. Spectrosc., 138, 1 (1989)]; these are en+1 = 〈Φ0RΦn〉 - Σm=1n em〈Φ0Φn-m〉 where R = 1/r2, Φ0 = ψv is the vibrational wave function (corresponding to the given energy Ev = e0) and Φ1, Φ2,…, are the “rotational corrections” to Φ0, solutions of the rotational (nonhomogeneous) Schrödinger equations. These equations are integrated by using a recent integrator using a powerful local control allowing (for Φ0) a high accuracy. The integrals are computed by using another powerful technique tailored for matrix elements between numerical wave functions [Kobeissi et al., J. Comp. Chem., 10, 358 (1989)]. This numerical treatment is applied to the model Lennard-Jones potential and to the RKR potential of the I2 ground state. In both applications the CDC are computed up to e6 = Nv and e7 = Ov (these two are published for the first time), and up to the dissociation [up to v = 23 for the Lennard-Jones potential, and to v = 108 for the XΣ - I2 (RKR) potential]. © 1992 by John Wiley & Sons, Inc.
Type of Medium: