Variational calculation of the vibronic spectrum in the X²Π<inf>u</inf> electronic state of C<inf>6</inf>^–

Abstract

A variational approach for ab initio handling of the Renner–Teller effect in six-atomic molecules with linear equilibrium geometry is elaborated. A very simple model Hamiltonian suitable for the description of small-amplitude bending vibrations in Π electronic states of arbitrary spin multiplicity was employed. The computer program developed within the framework of the present study was tested on the example of the X2Πu state of C6–. The results are compared with those generated in corresponding perturbative calculations.