Pseudopotential Studies of Structural Properties for Transition Metals

Abstract

Modern applications of the density functional theory within the “local density approximation” have demonstrated that the theory provides a powerful approach for studying the structural properties of solids. This method is generally regarded as a nonempirical theory, since once the density functional method is adopted, the only remaining input required for the calculation of ground state structural properties is the atomic number of the elements in the structures to be studied. In most applications to date, the formalism has proven exceedingly useful for ground state structural properties (i.e. predictions of equilibrium crystal structures, lattice constants and compressibilities). The prediction of absolute cohesive energies remains somewhat problematic, limited by the accuracy of the local density functional for calculating the absolute internal energy of the interacting many electron system. In this paper I will review some recent progress in extending the “first principles pseudopotential” approach to complex structures involving elements from the 3d transition series. For several reasons mentioned below, these systems have been resistant to well controlled studies on complex structures using available computational techniques. Here, I will briefly present a computational scheme which allows for accurate work on these systems, and will illustrate it with a brief review of results we have obtained on structural studies in Cu and NiAl.