The coherent potential approximation is generalized for application to quaternary alloys of the types AxCyB1-x-yD and AxB1-xCyD1-y. Formalisms are developed for and application is made to the calculation of the phonon spectra of random, mass-disordered quaternary alloys of both types in one dimension.
- coherent potential
- one-dimension and phonon spectra
- quaternary alloys