Search for General Features in Cation-Ligand Binding. AB initio SCF Studies of the Interaction of Alkali and Alkaline Earth Ions with Water

Abstract

We have investigated recently the possibility of utilization of SCF ab initio computation for the study of the interactions of alkali and alkaline-Earth cations with various ligands and explored the reliability in this respect of the possible combinations of different basis sets on the cation and the ligand. The technical aspect and conclusions of this study are presented elsewhere [1]. Broadly speaking it was shown that the poor results obtained with a standard minimal STO 3G basis set were due partly to the poor intrinsic representation it gives of the ligand and to the simultaneous overavailability of empty orbitals on the cation, leading to a spurious charge-transfer stabilization of the complex. Successive improvements of the representation of the cation and of the ligand have shown that reasonable binding characteristics may be obtained using a good atomic minimal basis.