Models of monovalent ions dissolved in water

A computational study on water-ions clusters for six ions (N[H.sub.4.sup.+], [F.sup.-], [Cl.sup.-], [Li.sup.+], [Na.sup.+], and [K.sup.+]) is described. Restricted Hartree-Fock method with 6- 31[G.sup.*] basis set was used to optimize the investigated water ion-clusters. Stable ion-water clusters proved to form with four (N[H.sub.4.sup.+] x 4[H.sub.2]O and [Li.sup.+] x 4[H.sub.2]O), five ([Cl.sup.-] x 5[H.sub.2]O and [Na.sup.+] x 5[H.sub.2]O) and respectively six water molecules ([F.sup.-] x 6[H.sub.2]O and [K.sup.+] x 6[H.sub.2]O). The arrangement of water molecules around the investigated ions proved not be symmetrical. Furthermore, the investigation of the stability of dodecahedral cages constructed with the investigated ions showed a stable symmetry for [O.sub.12][N.sub.8][H.sub.50], [O.sub.12][Li.sub.8][H.sub.18], and [O.sub.15][K.sub.5][H.sub.29]. Keywords: ion-water cluster; monovalent ion; stabilization