A simple fragment-based method for van der Waals corrections over density functional theory

Modelling intermolecular noncovalent interactions between large molecules remains a challenge for electron structure theory community. This is due to the high cost of calculating electron correlation energy. Fragment-based methods usually fare well in reducing the cost of computations in such systems while quantum Drude oscillators turn out to be a good model for van der Waals interactions. In this paper, we have developed a simple yet effective method based on oscillator methods for calculating van der Waals interactions between molecular fragments as a correction to low-cost DFT functional PBE. We have tested our method on S66X8 with significant success.

Coupling Parameters for Modeling the Near-Field Heat Transfer Between Molecules

The behavior of near-field heat transfer between molecules at gaps which are small compared to wavelength of light is greatly influenced by non-radiative dipole-dipole interactions between the molecules. Here we derive the coupling parameters and estimate the near-field heat transfer between two molecules using coupled Drude oscillators. The predictions from this model are verified with results from standard fluctuational electrodynamics principles. The effect of orientation factor of the dipole moments in the molecules traditionally taken into consideration for analysis of resonance energy transfer between molecules but hitherto overlooked for near-field heat transfer is also discussed.

Comparing induced point-dipoles and Drude oscillators

This work compares the two major methods to introduce polarisability in Molecular Dynamics simulations: induced point-dipoles and Drude oscillators.