Invariant expansion coefficients of the molecular pair correlation function of ZX4-systems

The general relationship between atom pair correlation functions gαβ(R) and the expansion coefficients gn1n2l1l2l12(R12) of the generalized pair correlation function g(R12, Ω1, Ω2, Ω12) is presented and tested numerically with the aid of the results of a computer simulation of liquid CCl4. For the structure factor of ZX4-systems a symmetry adapted expansion in terms of gn1n2l1l2l12(R12) is given together with the corresponding molecular form factors. In evaluating the g-coefficients a cartesian representation was used instead of Eulerian angles. It is shown how one can extract principal molecular configurations by a detailed g-coefficient analysis. (orig.)