A quantum Monte Carlo study on electron correlation in all-metal aromatic clusters MAl4(-) (M = Li, Na, K, Rb, Cu, Ag and Au).

Using fixed-node diffusion quantum Monte Carlo (FN-DMC) simulation we investigate the electron correlation in all-metal aromatic clusters MAl4(-) (with M = Li, Na, K, Rb, Cu, Ag and Au). The electron detachment energies and electron affinities of the clusters are obtained. The vertical electron detachment energies obtained from the FN-DMC calculations are in very good agreement with the available experimental results.