Simulation of Linear and Cyclic Alkanes with Second-Order Møller-Plesset Perturbation Theory through Adaptive Force
1Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, United States.
Journal of Chemical Theory and Computation
|June 7, 2024
Summary
Adaptive force matching (AFM) accurately predicts hydrocarbon properties like density and vaporization heat. This method achieves post-Hartree-Fock simulation quality using molecular mechanics force fields.
Area of Science:
- Computational chemistry
- Molecular modeling
Background:
- Predicting properties of small hydrocarbons is difficult due to weak intermolecular interactions.
- Accurate simulation requires advanced quantum chemical methods, which are computationally expensive.
Purpose of the Study:
- To develop a reliable method for predicting ensemble properties of small hydrocarbons.
- To enable simulations at post-Hartree-Fock quality with reduced computational cost.
Main Methods:
- Employed adaptive force matching (AFM) to fit bonded and nonbonded interactions.
- Utilized second-order Møller-Plesset perturbation theory (MP2) and symmetry adapted perturbation theory (SAPT) for reference calculations.
- Developed a novel charge matrix decomposition technique for partial charge determination.
Main Results:
- Achieved quantitative agreement between predicted and experimental properties, including density, heat of vaporization, diffusion constants, and surface tension.
- Demonstrated high accuracy for heat of vaporization (within 0.5% of experimental values).
- Identified potential for minor systematic error in density due to missing three-body dispersion.
Conclusions:
- Adaptive force matching (AFM) provides a reliable approach for accurate hydrocarbon simulations.
- The developed models offer post-Hartree-Fock simulation quality at a cost comparable to molecular mechanics force fields.
- This method significantly advances the capability for simulating weak interactions in molecular systems.
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