Ab initio MO study of solvated negative alkali atom clusters: [M(H 2O) n] − and [M(NH 3) n] − (M  Na and Li, n = 1−3)

Abstract

The structures, stabilities and vertical electron detachment energies (VDEs) of [Na(H 2O) n ] −, [Na(NH 3) n ] − and [Li(NH 3) n ] − ( n = 1−3) are investigated by the ab initio MO method at the correlated level. The NaH interactions and hydrogen bonds are important in [Na(H 2O) n ] −, while the metal-N bonds become essential in stabilizing the [Na(NH 3) n ] − and [Li(NH 3) n ] − with increasing n. The size dependence of the VDEs of [Na(H 2O) n ] − differs from that of [Na(NH 3) n ] − and [Li(NH 3) n ] − due to their structural features. In addition, the geometries and VDEs of [Li(H 2O) n ] − ( n = 1−3) are predicted theoretically. The size dependence of their VDEs is similar to that of [Na(NH 3) n ] − and [Li(NH 3) n ] − rather than [Na(H 2O) n ] −.