On the importance of accounting for nuclear quantum effects in ab initio calibrated force fields in biological simulations
| Autor: | Ganesh Kamath, Roger D. Kornberg, I. V. Leontyev, Leonid Pereyaslavets, Michael Levitt, M. A. Olevanov, Oleg Butin, Igor V. Kurnikov, Alexey A. Illarionov, Boris Fain |
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| Rok vydání: | 2018 |
| Předmět: |
Ab initio
nuclear quantum effect 010402 general chemistry Models Biological Corrections 01 natural sciences Force field (chemistry) Nuclear quantum effect Atomic motion Quantum mechanics 0103 physical sciences Path integral molecular dynamics Multidisciplinary 010304 chemical physics ab initio force field Interaction model Biological Sciences 0104 chemical sciences Chemistry Biophysics and Computational Biology Chemical species path integral molecular dynamics Physical Sciences Quantum Theory alkanes |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | Significance In molecular modeling the motion of nuclei, especially hydrogen, cannot be described using the laws of classical mechanics. The importance of nuclear quantum effects has long been appreciated by the ab initio molecular dynamics and by the water simulation communities. However, the vast majority of simulations of biological systems performed at ambient conditions treat atomic motion classically. Even in the new-generation force fields parameterized from quantum mechanics these effects are thought to be minor compared with other inaccuracies at room temperature and pressure. We show that a force field in excellent agreement with quantum mechanical energies and forces will not produce acceptably inaccurate predictions at ambient conditions unless the nuclear motion and interaction are accounted for in the simulation. In many important processes in chemistry, physics, and biology the nuclear degrees of freedom cannot be described using the laws of classical mechanics. At the same time, the vast majority of molecular simulations that employ wide-coverage force fields treat atomic motion classically. In light of the increasing desire for and accelerated development of quantum mechanics (QM)-parameterized interaction models, we reexamine whether the classical treatment is sufficient for a simple but crucial chemical species: alkanes. We show that when using an interaction model or force field in excellent agreement with the “gold standard” QM data, even very basic simulated properties of liquid alkanes, such as densities and heats of vaporization, deviate significantly from experimental values. Inclusion of nuclear quantum effects via techniques that treat nuclear degrees of freedom using the laws of classical mechanics brings the simulated properties much closer to reality. |
| Databáze: | OpenAIRE |
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