EXTENSION OF A LOCAL-ORBITAL DENSITY-FUNCTIONAL METHOD TO TRANSITION-METALS - APPLICATION TO PT(110) SURFACE RELAXATION

We report the extension of the highly efficient local-orbital molecula r-dynamics method originally developed by Sankey and Niklewski and lat er modified by Tsai et al. to include charge transfer to single-elemen t transition-metal systems. We have successfully added d orbitals to t he formalism and have eliminated the original spherical approximation for treating atomic charges by calculating the total charge density se lf-consistently from the absolute squares of wave functions of occupie d eigenstates. Test calculations for bulk Rh and Pt yield lattice cons tants and bulk modulii in excellent agreement with experiment and band structures in reasonable agreement with more accurate local-density a pproximation results. An application to the (2X1) reconstructed missin g row Pt(110) surface gives a relaxed geometry consistent with previou s calculations. Difficulties encountered in a simplified Harris-functi onal treatment of this same problem are discussed.