Solvation and Embedding Methods in Q-Chem

Are you studying a biomolecule in a complex environment? Do you want to know why that one reaction is more favorable if you use a polar solvent? Q-Chem has you covered. Our program comes with a variety of implicit solvent models, including SM8, C-PCM, and COSMO, as well as explicit solvent modeling. Additionally, we provide QM/MM functionality and several density embedding methods, as well as interfaces to popular packages CHARMM and GROMACS.

  • Implicit solvation models

    • SM8, SM12, SMD, COSMO, C-PCM,  SS(V)PE, IEF-PCM, CMIRS, and more

    • Intrinsically smooth discretization of the solute/continuum interface

    • Poisson equation solver for anisotropic dielectric boundary conditions


  • Effective fragment potential (EFP) for modeling explicit solvent with polarizable embedding

    • Built-in library of effective fragments and user-defined potentials

    • Available for DFT and wave function-based ground and excited state methods

    • Fragmented EFP scheme for macromolecules


  • Stand-alone QM/MM capabilities

    • Available for ground- or excited-state QM treatments

    • “Yin-Yang atom” approach to  defining the QM/MM boundary

    • Integration with PCM models (QC/MM/PCM)

    • Many-body expansion for incorporating solvent at a QM level


  • Interface to CHARMM and GROMACS


  • Density embedding methods

    • Projected-based density embedding for DFT-in-DFT or WFT-in-DFT

    • Frozen-Density embedding theory (FDET) and polarizable embedding (PE via EFP) for Algebraic Diagrammatic Construction (ADC) scheme