It was shown that the Brillouin zone integral for the interstitial KKR Green’s function could be accurately evaluated by taking proper account of free-electron singularities in the integrand. The method combined 2 recently developed methods: a super-matrix method and a subtraction method. This combination appeared to provide a major improvement when compared with earlier proposals that were based upon the subtraction principle alone. As a result, one obstruction to the study of important interstitial-like defects, such as an electromigrating atom half-way along its jump path, had been removed.

J.P.Dekker, A.Lodder, R.Zeller, A.F.Tatarchenko: Physical Review B, 1996, 54[7], 4531-9