Contact transformations in tensor formalism. Effective Hamiltonian and dipole moment for the v2, v4 dyad of tetrahedral molecules

Abstract

Simultaneous unitary transformations of the effective Hamiltonian and the effective dipole moment are studied via an irreducible tensor formalism for the v 2, v 4 dyad of tetrahedral molecules. Large unitary transformations relating resonance and isolated band models are treated by taking into account the non-leading contributions and multiple commutators. The unitary equivalence of different parameter sets of the effective dipole moment is explicitly shown for the v 2, v 4 bands of 12CH 4.