RT Journal Article
SR Electronic
T1 On the importance of accounting for nuclear quantum effects in ab initio calibrated force fields in biological simulations
JF Proceedings of the National Academy of Sciences
JO Proc Natl Acad Sci USA
FD National Academy of Sciences
SP 8878
OP 8882
DO 10.1073/pnas.1806064115
VO 115
IS 36
A1 Pereyaslavets, Leonid
A1 Kurnikov, Igor
A1 Kamath, Ganesh
A1 Butin, Oleg
A1 Illarionov, Alexey
A1 Leontyev, Igor
A1 Olevanov, Michael
A1 Levitt, Michael
A1 Kornberg, Roger D.
A1 Fain, Boris
YR 2018
UL http://www.pnas.org/content/115/36/8878.abstract
AB 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.