Theoretical study of the electron affinities of Cu, Cu2, and Cu3

Abstract

Modified coupled pair functional (MCPF) calculations are shown to yield the electron affinities of Cu, Cu2, and Cu3 to nearly equal accuracy. The structural results for Cu−3, together with the experimental negative ion photoelectron results, show conclusively that Cu−3 is linear in its (1Σ+g) ground state. The weak feature in the Cu−3 photoelectron spectrum at an electron binding energy of 1.5 eV is due to ionization from the 3A′2 (equilateral triangle) excited state of Cu−3.