Explicit polarization: a quantum mechanical framework for developing next generation force fields.
Jiali Gao1, Donald G Truhlar, Yingjie Wang
1Theoretical Chemistry Institute, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University , Changchun, Jilin Province 130028, People's Republic of China.
Accounts of Chemical Research
|August 8, 2014
Summary
A new quantum mechanical force field (QMFF) strategy, explicit polarization (X-Pol), improves biomolecular simulations by treating electronic polarization explicitly. This quantum mechanical force field approach enhances accuracy for predicting interactions and properties beyond classical methods.
Area of Science:
- Computational Chemistry
- Biophysics
- Materials Science
Background:
- Classical molecular force fields have modeled condensed-phase and biological systems for decades.
- Current force fields require improved accuracy for quantitative prediction of biomolecular interactions and wave-function-dependent properties.
- Limitations exist in classical force fields for modeling spectroscopy, reactivity, and enzyme catalysis.
Purpose of the Study:
- Introduce explicit polarization (X-Pol) as a quantum mechanical force field (QMFF) strategy.
- Develop a new computational approach for potential energy surfaces and wave functions in simulations.
- Enhance the accuracy of biomolecular simulations beyond classical force field capabilities.
Main Methods:
- Developed X-Pol, a fragment-based quantum mechanical method for electronic structure calculations.
- Employed a variational many-body (VMB) expansion to systematically improve interfragment interactions.
- Applied X-Pol in full variationally correct and faster embedded versions with many-body improvements.
Main Results:
- X-Pol accurately models water clusters, demonstrating the power of two-body corrections.
- Simulations of ionic liquids show less charge transfer than previously assumed in classical models.
- Revealed sequence-dependent charge distribution in protein carbonyl groups, a feature absent in classical force fields.
Conclusions:
- X-Pol offers a new generation of force fields with improved accuracy for biomolecular simulations.
- This QMFF approach extends computational capabilities to areas like spectroscopy, reactivity, and enzyme catalysis.
- X-Pol provides a more accurate representation of electronic polarization and wave functions in condensed-phase and macromolecular systems.
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