Novel structures for the excess electron state of the water hexamer and the interaction forces governing the structures

The geometrical and electronic structures of partially hydrated electron systems, in particular, the water hexamer, which have been controversial for decades, have been clarified by an exhaustive search for possible low-lying energy structures. Several competing interaction forces governing the conformation have been examined for the first time. The low-lying energy structures are hybrid (or partially internal and partially surface) excess electron states. Our prediction is evidenced from excellent agreements with available experimental data. The vertical electron-detachment energies are mainly determined by the number of dangling H atoms (H-d).