Permutation-Inversion Group of Fullerite C₇₀ in the Intermediate Phase

The permutation-inversion symmetry group of fullerite C₇₀ in the intermediate phase (at temperatures 270 K < T < 340 K) and the permutation-inversion site symmetry group of a rotating molecule C₇₀ in a nonrigid crystal are generated. Their irreducible representations compatible with the principle of symmetry of wave functions with respect to the permutations of identical nuclei are found. Group-theoretical classification of quantum-mechanical states of a rotating molecule and a crystal in the intermediate phase of fullerite C₇₀ is made. The selection rules for electronic and IR spectra in terms of the irreducible representations of the permutation-inversion group are found.