The nature of three-body interactions in DFT: exchange and polarization effects
Autor: | Rainer Schäffer, Marcin Modrzejewski, Michał Hapka, Małgorzata M. Szczęśniak, Łukasz Rajchel, Grzegorz Chałasiński |
---|---|
Rok vydání: | 2017 |
Předmět: |
Physics
Chemical Physics (physics.chem-ph) 010304 chemical physics Component (thermodynamics) Exchange interaction Chemie General Physics and Astronomy FOS: Physical sciences Trimer Function (mathematics) 010402 general chemistry Polarization (waves) 01 natural sciences 0104 chemical sciences symbols.namesake Pauli exclusion principle Chemical physics Physics - Chemical Physics 0103 physical sciences Atom symbols Physical and Theoretical Chemistry van der Waals force |
DOI: | 10.48550/arxiv.1706.07982 |
Popis: | We propose a physically motivated decomposition of DFT 3-body nonadditive interaction energies into the exchange and density-deformation (polarization) components. The exchange component represents the effect of the Pauli exclusion in the wave function of the trimer and is found to be challenging for density functional approximations (DFAs). The remaining density-deformation nonadditivity is less dependent upon the DFAs. Numerical demonstration is carried out for rare gas atom trimers, Ar$_2$-HX (X = F, Cl) complexes, and small hydrogen-bonded and van der Waals molecular systems. None of the tested semilocal, hybrid, and range-separated DFAs properly accounts for the nonadditive exchange in dispersion-bonded trimers. By contrast, for hydrogen-bonded systems range-separated hybrids achieve a qualitative agreement to within 20% of the reference exchange energy. A reliable performance for all systems is obtained only when the monomers interact through the Hartree-Fock potential in the dispersion-free Pauli Blockade scheme. Additionally, we identify the nonadditive second-order exchange-dispersion energy as an important but overlooked contribution in force-field-like dispersion corrections. Our results suggest that range-separated functionals do not include this component although semilocal and global hybrid DFAs appear to imitate it in the short range. |
Databáze: | OpenAIRE |
Externí odkaz: |