XSAPT+aiD Interaction Energies and Energy Decomposition Analysis

  • Benchmark-quality intermolecular interaction energies.

  • Energy decomposition analysis provides a powerful interpretive utility.

  • Unfolds interaction energies into contributions from electrostatics, Pauli repulsion, polarization, and London dispersion.

  • A fully many-body interaction energy protocol:

    • Accounts for many-body polarization effects via charge embedding.

    • Soon to include many-body dispersion interactions (MBD+esDQ potential) in Q-Chem v5.3.

  • Cost scales with monomer size; no need for supersystem calculations.

  • Faster than supersystem DFT for the DNA complex shown above (4,651 basis functions)

  • Trivially parallelizable across fragments.

  • Capable of high-accuracy interaction energies in systems larger than 10,000 basis functions.