Abstract
In this paper the first-principles generalized pseudopotential theory (GPT) of transition-metal interatomic potentials [J. A. Moriarty, Phys. Rev. B 38, 3199 (1988)] is extended to binary compounds and alloys. For general transition-metal (TM) systems, the GPT total-energy functional involves a volume term, central-force pair potentials, and angular-force multi-ion potentials, which are both volume and concentration dependent and include all and interactions within local density-functional quantum mechanics. The formalism is developed here in detail for intermetallic systems where is a simple metal and is a transition metal and applied to the prominent special case of the transition-metal aluminides where hybridization is especially important. Emphasis is given to the aluminum-rich binary systems for which appear to be well described at the pair-potential level without angular forces and for which the present GPT potentials can be used directly in atomistic simulations. Volume terms and pair potentials for all of the aluminides have been calculated and their behavior with atomic number, and is elaborated through illustrative applications to the cohesive and structural trends across the series. More extensive applications to the Co-Al and Ni-Al phase diagrams will be given elsewhere.
- Received 17 April 1997
DOI:https://doi.org/10.1103/PhysRevB.56.7905
©1997 American Physical Society