Vibrational properties of NixPt1-xalloys

Abstract
The augmented space technique introduced by one of the authors is used here to study the vibrational properties of NixPt1-x alloys at various concentrations. The 1CPA has proved to give results in poor agreement with experiment. Strong disorder in both mass and force constant has been quoted as being responsible. The CCPA results confirm this and are found to be in much better agreement. The authors incorporate statistically correlated diagonal and off-diagonal disorders correctly, as well as the force constant sum rules.