MONTE-CARLO SIMULATIONS OF COPPER CHLORIDE SOLUTIONS AT VARIOUS CONCENTRATIONS INCLUDING FULL 3-BODY CORRECTION TERMS

Aqueous copper chloride solutions at concentrations of 1, 3 and 5 mol kg(-1) have been investigated by means of Metropolis Monte Carlo simul ations. The structural results are compared with experimental data on species formation and structure of these solutions. As pair potentials are insufficient to describe solvation phenomena correctly, three-bod y terms were incorporated, based on ab initio calculations for the int eractions Cu2+-H2O-H2O and Cu2+-Cl--H2O. The simulations were performe d with three-body correction for the Cu2+-H2O-H2O alone and with three -body corrections for both Cu2+-H2O-H2O and Cu2+-Cl--H2O. The structur e of the solvated copper(II) ion is discussed in terms of radial densi ty functions and coordination number distributions. The correction of the Cu2+-Cl--H2O interactions proved absolutely necessary to achieve r eliable structural results, whereas three-body effects corresponding t o Cl--Cu2+-Cl- interactions could be neglected, since in most species two chloride ions are located in trans-positions. (C) 1997 Elsevier Sc ience B.V.