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Variationally derived intermediates for correlated free-energy estimates between intermediate states
Martin Reinhardt1, Helmut Grubmüller1
1Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
Physical Review. E
|November 20, 2020
Summary
Calculating free-energy differences using atomistic simulations is more accurate with intermediate states. This study develops a new method to optimize these states and estimators, accounting for correlations for improved accuracy.
Area of Science:
- Computational chemistry
- Statistical mechanics
- Molecular dynamics
Background:
- Free-energy calculations are crucial in chemistry and materials science.
- Current methods often use intermediate thermodynamic states for accuracy.
- Efficiency concerns lead to approximations that violate statistical assumptions.
Purpose of the Study:
- To develop an optimal sequence of intermediate states for free-energy calculations.
- To derive a new estimator that accounts for correlations between states.
- To minimize the mean-squared error in free-energy difference calculations.
Main Methods:
- Variational approach to derive optimal intermediate states.
- Development of a novel statistical estimator.
- Analysis of correlations between sampled states.
Main Results:
- A sequence of intermediate states that minimizes mean-squared error was derived.
- A new estimator accounting for correlations was developed.
- The accuracy of the new approach was assessed.
Conclusions:
- The proposed method improves accuracy in free-energy calculations.
- Accounting for correlations is essential for optimal state selection and estimation.
- This work provides a more robust framework for atomistic free-energy simulations.
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