Fast and versatile method for full-potential total energies: Applications to ordered and disordered alloys

A fast linearized method for electronic-structure calculations is introduced and shown to be applicable to disordered alloys and a variety of other systems. The method allows a full-potential solution to the local-density-approximation equations for both ordered and substitutional alloys. The method was used for the challenging problems of evaluating the elastic constants and the relaxation around impurities. As a demonstration of the applicability of the method for more open structures, the vibrational frequencies of doped fullerenes were successfully calculated.