Structural Optimization and D-Band Holes in Cu Monolayers

摘要

The equilibrium lattice parameter and band structure of copper monolayers, bothin the square (100) and hexagonal (111) symmetry, have been determined using self-consistent full-potential local density approximation (LDA) calculations. Two quite different procedures have been employed: FILMS, a linear-combination-of-gaussian type-orbitals methods, and a full-potential linearized augmented plane wave (F-LAPW) method. The copper monolayer is bound with respect to the atomic LSDA ground state. Nearest neighbor distances are determined as 4.25 a.u. in the square geometry and 4.42 a.u. in hexagonal geometry, the latter being favored in energy by 0.33 eV/atom. Both monolayers thus exhibit a nearest-neighbor distance substantially shorter than that found in bulk copper.