Analytical nuclear gradients for the range-separated many-body dispersion model of noncovalent interactions
| Autor: | Alán Aspuru-Guzik, Martin A. Blood-Forsythe, Roberto Car, Thomas Markovich, Robert A. DiStasio |
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| Rok vydání: | 2015 |
| Předmět: |
FOS: Physical sciences
01 natural sciences Molecular physics symbols.namesake Physics - Chemical Physics 0103 physical sciences Non-covalent interactions 010306 general physics Wave function Harmonic oscillator Physics chemistry.chemical_classification Chemical Physics (physics.chem-ph) 010304 chemical physics Electronic correlation Intermolecular force Charge density General Chemistry Computational Physics (physics.comp-ph) 3. Good health Chemistry chemistry symbols Density functional theory van der Waals force Physics - Computational Physics |
| Zdroj: | Chemical Science |
| DOI: | 10.48550/arxiv.1509.00480 |
| Popis: | Accurate treatment of the long-range electron correlation energy, including van der Waals (vdW) or dispersion interactions, is essential for describing the structure, dynamics, and function of a wide variety of systems. Among the most accurate models for including dispersion into density functional theory (DFT) is the range-separated many-body dispersion (MBD) method [A. Ambrossetti et al., J. Chem. Phys. 140, 18A508 (2014)], in which the correlation energy is modeled at short-range by a semi-local density functional and at long-range by a model system of coupled quantum harmonic oscillators. In this work, we develop analytical gradients of the MBD energy with respect to nuclear coordinates, including all implicit coordinate dependencies arising from the partitioning of the charge density into Hirshfeld effective volumes. To demonstrate the efficiency and accuracy of these MBD gradients for geometry optimizations of systems with intermolecular and intramolecular interactions, we optimized conformers of the benzene dimer and isolated small peptides with aromatic side-chains. We find excellent agreement with the wavefunction theory reference geometries of these systems (at a fraction of the computational cost) and find that MBD consistently outperforms the popular TS and D3(BJ) dispersion corrections. To demonstrate the performance of the MBD model on a larger system with supramolecular interactions, we optimized the C$_{60}$@C$_{60}$H$_{28}$ buckyball catcher host-guest complex. Finally, we find that neglecting the implicit nuclear coordinate dependence arising from the charge density partitioning, as has been done in prior numerical treatments, leads to an unacceptable error in the MBD forces, with relative errors of ~20% (on average) that can extend well beyond 100%. Comment: 18 pages including 5 figures; plus 9 pages supplementary information including 5 additional figures |
| Databáze: | OpenAIRE |
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