A force field for acetone: the transition from small clusters to liquid phase investigated by molecular dynamics simulations

Abstract

A new semiempirical force field for the intermolecular (CH $$_{3}$$ –CO–CH $$_{3}$$ )–(CH $$_{3}$$ –CO–CH $$_{3}$$ ) interaction has been built and applied to characterize the acetone behavior in different environments. Molecular dynamics simulations of some small clusters and liquid phase have been carried out. In particular, the behavior of the dimer and the trimer has been analyzed considering a microcanonical ensemble (NVE). Predictions of the (CH $$_{3}$$ –CO–CH $$_{3}$$ ) $$_{2-3}$$ binding energies have been provided by extrapolating to 0 K the mean potential energy values evaluated at low temperatures. The probability of isomerization processes has been also analyzed. Molecular dynamics simulations for liquid acetone have been performed, to test the generality of the force field formulation, considering an isothermal–isobaric (NpT ensemble) of 1000 molecules. Different conditions of pressure and temperature have been taken into account. Structural details of liquid have been analyzed through some relevant radial distribution functions, from which the coordination number has been evaluated. The model predictions for both small clusters and liquid acetone have been compared successfully with available experimental and/or theoretical results.