CHARGE-TRANSFER EFFECTS IN DISORDERED ALLOYS - THE TEST-CASE OF AL-LIALLOYS

A general method for treating the so-called charge-transfer effects in substitutional alloys is suggested within the formalism of the single -site (SS) coherent-potential approximation (CPA). The method allows t he self-consistent treatment of the Poisson field through the construc tion of a configurational space and species-dependent structure consta nts which provide the means for an application of multiple-scattering theory which avoids overlap between adjacent cells. This, in rum, allo ws the treatment of non-neutral cells at the level of the SS CPA, avoi ding the need for subsequent correction the results of the CPA. The me thod is compared with previous approaches to the problem and is used t o treat the case of Al-Li alloys for which significant charge transfer is known to exist. The results are compared with those obtained withi n the muffin-tin implementation of the CPA, and a final discussion of the general features of the proposed method is given.