Symmetry-adapted perturbation theory for cavity-modified intermolecular interactions: QED-SAPT0 theory and implementation
Year: 2026
Type: preprint
Abstract: We develop a cavity quantum electrodynamics symmetry adapted perturbation theory (QED-SAPT) formalism that directly models intermolecular interactions in quantized cavity environments. By formulating the zeroth-order problem in a coherent state basis, we define the inter-monomer perturbation as the sum of the standard Coulombic contribution and an inter-monomer dipole self energy contribution. This yields a particularly convenient structure whereby the new inter-monomer cavity components can be incorporated through a simple augmentation of the dressed integrals that arise in standard SAPT theory. We also leverage this structure in a density fitted implementation and demonstrate the performance advantage over an implementation that utilizes the full electron integral tensor. Finally, we utilize this formalism to explore several representative molecular clusters from the S66 data set and provide comparison to QED-CCSD and QED-DFT formalisms.
Source: ChemRxiv
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223152049