Geometries and energy separations of low-lying electronic states of Zr 5 with different structures have been investigated by complete active space multi-configuration self-consistent field method followed by large-scale multi-reference singles + doubles configuration interaction computations that included up to 3 million configurations. Three nearly degenerate electronic states, namely 3 A 2 (C 2 v ) with a distorted tetragonal pyramid structure and 1 A and 5 A (C s ) with distorted edge capped tetrahedral geometries were found as the candidates for the ground state of Zr 5 . The atomization and dissociation energies have been calculated and compared with smaller clusters.