A theoretical study of Na(H2O)+n (n=1–4)

The successive H2O binding energies of Na(H2O)+n are in excellent agreement with experiment and are rather insensitive to electron correlation since the bonding is predominantly electrostatic. A point-charge model shows that changes in the successive binding energies are due primarily to ligand–ligand repulsion. Vibrational frequencies and infrared intensities are determined for Na(H2O)+n (n=1–4) at the self-consistent-field and second-order Mo/ller–Plesset levels of theory to facilitate experimental study of these ions.