Stark energies for molecules with vibrationally induced dipole moments

Permanent Dipole Moments of Methane-Type Molecules: Calculation of the DeltaJ = 0 Matrix Elements in the l = 1 Vibrational State

We examined permanent dipole moments (PDMs) of methane-type molecules induced by molecular internal motions which are expanded in terms of the vibrational coordinate operator q , total angular momentum operator J , and vibrational angular momentum operator l . The qq -, JJ -, Jl -, and ll -type quadratic terms of these operators contribute to the production of PDMs. The DeltaJ = 0 matrix elements of the four PDMs are calculated for the first excited state of the triply degenerate vibrational mode; a portion are numerically given in a table for the J </= 6 levels. We have also compared them with the PDM represented by the rotational angular momentum operator R = J - l and discussed an application of the present calculations to the v 3 = 2 state of methane.