Optimized Quantum Drude Oscillators for Atomic and Molecular Response Properties

The quantum Drude oscillator (QDO) is an efficient yetaccuratecoarse-grained approach that has been widely used to model electronicand optical response properties of atoms and molecules as well aspolarization and dispersion interactions between them. Three effectiveparameters (frequency, mass, and charge) fully characterize the QDOHamiltonian and are adjusted to reproduce response properties. However,the soaring success of coupled QDOs for many-atomsystems remains fundamentally unexplained, and the optimal mappingbetween atoms/molecules and oscillators has not been established.Here we present an optimized parametrization (OQDO) where the parametersare fixed by using only dipolar properties. For the periodic tableof elements as well as small molecules, our model accurately reproducesatomic (spatial) polarization potentials and multipolar dispersioncoefficients, elucidating the high promise of the presented modelin the development of next-generation quantum-mechanical force fieldsfor (bio)molecular simulations.

Automated summary

The quantum Drude oscillator (QDO) is an efficient coarse-grained approach used to model electronic and optical response properties of atoms and molecules. An optimized parametrization (OQDO) is presented in this study, where the parameters are fixed using only dipolar properties. The OQDO accurately reproduces atomic polarization potentials and multipolar dispersion coefficients for the periodic table of elements and small molecules, showing great potential in the development of next-generation quantum-mechanical force fields for (bio)molecular simulations.