EXTENDED MOLECULAR SYMMETRY GROUPS: SYMMETRY ANALYSIS OF MOLECULES CONSISTING OF TWO COAXIAL ROTORS

A general method for constructing permutation-inversion groups and their extensions for molecules containing two coaxial rotors is presented. Precise techniques are given for construction of irreducible representations, and their systematic labeling is proposed. Species of the dipole moment, tensor of polarizability, and total angular momentum operators are determined. General infrared and Raman selection rules, classifications of rotorsional, rotational, and torsional wavefunctions are derived. Nuclear spin statistical weights are determined in general. Theory is illustrated for the and complexes.