Use of Molecular Simulation in Calculating a Characteristic Relative Growth Effect Curvature to Correlate Factors Influencing Crystalline Growth and Other Properties

The following report outlines a simplified method to predict the effect on the relative growth rates of crystal facets resulting from different solvents. The method uses molecular dynamics (MD) techniques which are coupled to a Monte Carlo (MC) scheme to generate distributions of estimates of molecular binding energies at the crystal surface. We then use these calculated binding energies to make inferences on how solvent may affect the relative growth rate of the crystal facets (i.e., solvent effect on growth). We support the analysis by revisiting the growth of adipic acid. It is demonstrated that there is a remarkable increase in the sensitivity of the expected values used to represent the “solvent effect on growth” when a very simple correction for the molecular size between solute and solvent is implemented into the Monte Carlo scheme. The use of single point energy calculations (potential energy) displays limited sensitivity to the expected solvent effect in comparison to the use of distributions of MD derived values (binding free energy). Thus, the combination of relative binding free energy data and the proposed MC scheme is believed to be an effective path forward to providing insight into a solvent or additive effect on growth for more complex molecular systems that is simple to implement and does not come at a significantly high computational expense. In order to make an assessment of the data from simulation, plotting of the relative growth effect curvature is also introduced