[en] A criterion for freezing of alkali halides in terms of the principal peak of the liquid charge-charge structure factor Ssub(QQ)(k) has been given in earlier work. Subsequently, a theory of freezing of both neutral binary alloys and alkali halides has been developed, based on partial liquid structure factors as input information. The purpose of the present letter is to report results calculated from this theory, using the neutron determined partial structure factors for RbCl. The important quantity for the present approach is the fractional volume change on melting (Vsub(L) - Vsub(S))/Vsub(S) is identical to eta, L and S referring to liquid and solid respectively