MD study of an infinitely dilute aqueous solution of formaldehyde using different ab initio potentials

A Molecular Dynamics calculation of an infinitely dilute aqueous solution of formaldehyde was carried out using the MCY potential for the water-water interaction and different ab initio potentials (including electronic correlation and basis set superposition effects) for the solute-solvent interaction. Various static and dynamic properties such as thermodynamic functions, radial distribution functions and coordination numbers, mean square displacements and diffusion coefficients, dipole autocorrelation functions and reorientation times, were calculated for this solute. The results show the need to use potentials which describe in an adequate and real form the solvation of the solute. Thus, the solute's hydration and solvation energy were observed to depend strongly on the calculation level used in evaluating the formaldehyde-water interaction energy, thereby conditioning the results for other properties. (C) 1997 Elsevier Science B.V.