Knowledge Bank

A theoretical formulation is presented within the framework of Anderson-Tsao-Curnutte theory for calculating the half-widths of spectral lines belonging to tetrahedral molecules. The importance of tetrahedral symmetry in the charge distribution and in the wave functions is emphasized. Expressions for the interruption functions $S2(b)$ have been derived for octopole-dipole, octopole-quadrupole, octopole-octopole, octopole-hexadecapole, hexadecapole-dipole, hexadecapole-quadrupole, hexadecapole-octopole, hexadecapole-hexadecapole, anisotropic dispersion interactions as well as for an assumed overlap interaction potential. The earlier theoretical work of Tejwani and Yamamoto and Hirono is shown to be inappropriate for molecules of tetrahedral symmetry.