Are the Lennard-Jones potential parameters endowed with transferability? Lessons learnt from noble gases

Although the accuracy of first-principles calculations makes them ideal for modeling noncovalent interactions, their high computational cost limits their applicability to moderate system sizes. Analytic potentials have emerged as an excellent means of modeling large-scale systems because of their simplicity and computational efficiency. However, the effectiveness of the analytic potentials depends heavily on the choice and the transferability of their parameters. Herein, employing noble gases as a testbed, we embarked on assessing the transferability of parameters of two widely used pair potentials, Lennard-Jones (LJ) and improved Lennard-Jones (ILJ) potentials. We established the inadequacy of the various traditional combination rules for the LJ potential in describing noble gas heterodimer interactions. The potentials that are parametrized against benchmark CCSD(T) calculations for noble gas homodimers and heterodimers failed to accurately describe the interactions in dimers of noble gas dimers. However, a parametrization of the LJ and the ILJ potentials against reference electronic structure calculations describing noble gas dimer-dimer interactions was found to be effective. The ILJ potential consistently exhibited improved accuracy over the LJ potential. Our study showcases the non-transferability of the LJ and the ILJ parametrizations developed for the elementary pairwise interactions to the description of complex chemical systems.