Quantum-classical solvation hydrodynamics: a Hamiltonian modeling framework

TL;DR

This paper introduces a Hamiltonian-based mixed quantum-classical hydrodynamic framework to model short-time non-adiabatic solvation dynamics, capturing inertial effects, decoherence, and solvent correlations efficiently.

Contribution

It develops a novel Hamiltonian modeling approach that incorporates backreaction, decoherence, and collective solvent effects in quantum solvation dynamics.

Findings

Retains essential solute-solvent correlations

Reduces computational complexity compared to previous models

Extends solvation theory with dielectric continuum and fluid sloshing

Abstract

We propose a mixed quantum-classical hydrodynamic framework to model short-time inertial effects in the non-adiabatic evolution of a quantum solute coupled to a classical polar solvent. Drawing upon the work of Burghardt and Bagchi [Chem. Phys. 329 (2006), 343], we employ the Hamiltonian approach to incorporate consistent backreaction and preserve quantum decoherence beyond standard Ehrenfest dynamics. The solvent is treated as an ideal polar fluid and the quantum solute state is coupled to both the position and molecular orientation coordinates of the liquid. This approach retains essential solute-solvent correlations while significantly reducing the computational complexity of previous approaches. We further incorporate dissipative terms to capture both inertial effects and polarization relaxation. After establishing the general setting for non-local dielectric continua, the Marcus local approximation is integrated into the model thereby extending traditional solvation theory to account for collective fluid sloshing on fast timescales.