Fully Polarizable\nMulticonfigurational Self-Consistent\nField/Fluctuating Charges Approach

A multiscale model based on the coupling of the multiconfigurational\nself-consistent field (MCSCF) method and the classical atomistic polarizable\nfluctuating charges (FQ) force field is presented. The resulting MCSCF/FQ\napproach is validated by exploiting the CASSCF scheme through application\nto compute vertical excitation energies of formaldehyde and <i>para</i>-nitroaniline in aqueous solution. The procedure is\nintegrated with molecular dynamics simulations to capture the solute’s\nconformational changes and the dynamic aspects of solvation. Comparative\nanalysis with alternative solvent models, gas-phase calculations,\nand experimental data provides insights into the model’s accuracy\nin reproducing solute–solvent molecular interactions and spectral\nsignals.