The Structure of Li7 and K7

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 the second most stable structure for Li7(-). A comparison of the computed separations between the low-lying states of K7 and the photoelectron detachment spectra does not allow an unambiguous assignment of the structure of K7(-).