A density functional study of small copper clusters: Cun (n⩽5)

Density functional calculations have been performed for small copper clusters, Cun (n≤5), using the linear combination of Gaussian-type orbitals density functional theory (LCGTO-DFT) approach. The calculations were of the all-electron type and local and nonlocal functionals were used. For each case, of both neutral and charged systems, several isomers have been considered in order to determine the lowest energy structures. The Jahn–Teller effect in Cu3 and Cu4 has been examined in detail. Bond lengths, equilibrium geometries, harmonic frequencies, adiabatic and vertical ionization potentials, adiabatic electron affinities, and binding energies are in reasonable agreement with experimental data, as well as with other theoretical results.