Embedding Quantum Statistical Excitations in a Classical Force Field

Quantum-mechanically-driven charge polarization and transfer are ubiquitous in biomolecular systems, controlling reaction rates, allosteric interactions, ligand-protein binding, membrane transport, dynamically-driven structural transformations. Molecular dynamics (MD) simulations of these processes require quantum mechanical (QM) information order to accurately describe their reactive dynamics. However, current techniques -- empirical force fields, subsystem approaches, ab initio MD, machine learning vary ability achieve a consistent chemical description across multiple atom types, at scale. Here we present physics-based, atomistic field, the ensemble DFT charge-transfer embedded-atom method, which QM forces described uniform level theory all atoms, avoiding need for explicit solution Schr\"{o}dinger equation or large, precomputed training datasets. Coupling between electronic length scales is effected through an density functional formulation embedded method originally developed elemental materials. Charge expressed terms ensembles ionic states basis densities individual polarization, atomic excited state densities. This provides highly compact yet general representation encompassing both local system-wide effects. rearrangement realized evolution weights, adjusted each dynamical timestep via potential equalization.