Abstract :
The self-consistent-field (SCF) approach and density functional theory, using the B3LYP hybrid functional, yield three low-lying structures for Li7−. The relative separations differ for the SCF and B3LYP approaches, however the B3LYP results are in good agreement with the coupled cluster results. For K7−, only an octahedron with one face capped is found to be a minimum; this is the second most stable structure for Li7−. A comparison of the computed separations between the low-lying states of Li7 and the photoelectron detachment spectra does not allow an unambiguous assignment of the structure of K7−.