Reduced Hamiltonian for 0100 and 0001 interacting states of tetrahedral XY 4 molecules: Calculated r 2J 2 and r 2J 3-type parameters for ν2 and ν4 bands of methane
Ambiguity of the effective Hamiltonian for the interacting E and F2 states of tetrahedral XY 4 molecules was studied. Unitary transformations to yield a reduced form of the Hamiltonian were suggested, the latter including only empirically determinable parameters. The r 2J 2 and r 2J 3-type spectroscopic parameters for the 0001 and 0100 dyad of CH 4 molecule were calculated by means of contact transformations. It was shown that sets of spectroscopic parameters derived by several authors for the interacting ν2 and ν4 bands of CH 4 and SiH 4 may be related via certain unitary transformations.