Improved modeling of anharmonicity for furan microsolvation.
Wassja A Kopp1, Matthias L Mödden1, Narasimhan Viswanathan1
1Institute of Technical Thermodynamics, RWTH Aachen University, 52062 Aachen, Germany. kai.leonhard@ltt.rwth-aachen.de.
Physical Chemistry Chemical Physics : PCCP
|April 5, 2023
Summary
This study introduces TAMkinTools for accurate hindered rotation modeling in complexes, standardizing workflows and improving computational benchmark data. It provides crucial zero-point energies, significantly impacting conformational analysis.
Area of Science:
- Computational Chemistry
- Molecular Modeling
- Quantum Chemistry
Background:
- Accurate computational benchmark data relies on precise modeling of anharmonic torsional motion.
- Current hindered rotor treatments face challenges like discontinuities, oscillations, and complex stationary point handling, introducing arbitrariness.
- Standardized, automated workflows are essential for reliable benchmark procedures.
Purpose of the Study:
- To present TAMkinTools, an extension for enhanced one-dimensional hindered rotation modeling.
- To enable a more standardized workflow for computational benchmark data generation.
- To evaluate the impact of zero-point energies on conformational analysis in molecular complexes.
Main Methods:
- Utilized the Goebench challenge dataset, including OH- and π-bonded complexes of methanol and furan derivatives.
- Employed various sizes of Ahlrichs and Dunning basis sets with extrapolations for coupled-cluster energy calculations.
- Applied probability density analysis within TAMkinTools for zero-point energy determination.
Main Results:
- TAMkinTools facilitates a standardized workflow for hindered rotation modeling.
- Basis set choice significantly impacts the efficiency and accuracy of coupled-cluster energy calculations.
- Zero-point energies calculated by TAMkinTools demonstrably affect conformational ordering, particularly for the methanol-furan complex.
Conclusions:
- TAMkinTools offers an improved approach to modeling hindered rotation, reducing arbitrariness in benchmark data.
- Accurate zero-point energy calculations are critical for determining the conformational landscape of molecular complexes.
- The study highlights the sensitivity of conformational energy differences to zero-point effects, especially for weakly bound systems.
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