Optimized all-atom force field for alkynes within the OPLS-AA framework

New transferrable all-atom force field parameters for alkynes are presented, to be used as an extension of the OPLS-AA force field. The alkyne-specific intramolecular parameters, as well as the atomic partial charges, are assessed with ab initio calculations. The dispersive interactions are optimized to reproduce the liquid densities and enthalpies of vaporization of a training set of compounds over a wide range of state conditions, through extensive molecular dynamics simulations. The accuracy and transferability of the proposed force field is tested for the same compounds at different temperatures and for compounds outside the training set.