In this work, the XDM model was used to obtain the London dispersion coefficients of 88 organic molecules relevant to biochemistry and pharmaceutical chemistry and the values compared with those derived from the Lennard-Jones parameters of the CGenFF, GAFF, OPLS, and Drude polarizable force fields. Alternatively, the exchange-hole dipole moment (XDM) model from density-functional theory predicts atomic and molecular London dispersion coefficients from first principles, providing an innovative strategy to validate the dispersion terms of molecular-mechanical force fields. These parameters are generally underdetermined, and there is no straightforward way to test if they are physically realistic. Force fields for atomistic molecular simulations typically represent dispersion interactions by the 12-6 Lennard-Jones potential using empirically determined parameters. London dispersion interactions play an integral role in materials science and biophysics. Mohebifar, Mohamad Johnson, Erin R Rowley, Christopher N Here, we present two qualitative studies of undergraduate general chemistry students' reasoning about the causes of London dispersion forces in…Įvaluating Force-Field London Dispersion Coefficients Using the Exchange-Hole Dipole Moment Model. Characterizing Students' Mechanistic Reasoning about London Dispersion ForcesĮRIC Educational Resources Information Centerīecker, Nicole Noyes, Keenan Cooper, MelanieĬharacterizing how students construct causal mechanistic explanations for chemical phenomena can provide us with important insights into the ways that students develop understanding of chemistry concepts.
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