A new ab initio potential was developed to describe the copper-water interactions. Since it is known that pair potentials are insufficient to describe solvation phenomena correctly, 3-body terms were incorporated, based on ab initio calculations. This potential leads to a first-shell coordination number of 6 in agreement with experimental data without too much increase in computational effort in a Monte Carlo simulation of an infinitely dilute solution. While evaluating 3-body interactions some considerable artifacts in the well known and often used CF2 water-water pair potential were discovered.