The 9th International Conference on Multiscale Materials Modeling

講演情報

Symposium

N. Towards Experimentally Relevant Time Scales: Methods for Extending Atomistic Simulation Times and Their Applications in Material Science

[SY-N4] Symposium N-4

2018年10月31日(水) 16:00 〜 17:30 Room4

Chair: Laurent Karim Beland(Queen's University, Canada)

[SY-N4] Accelerated Quantum Molecular Dynamics

Enrique Martinez Saez1, Christian Negre2, Romain Perriot2, Danny Perez2, Eduard Kober2, Marc Cawkwell2, Arthur F. Voter2, Anders Niklasson2 (1.Material Science and Technology Division, MST-8,Los Alamos National Laboratory, Los Alamos, 87545 NM, USA, United States of America, 2.Theoretical Division, T-1, Los Alamos National Laboratory, Los Alamos, 87545 NM, USA, United States of America)

The accurate study of the long-term evolution of rare events is extraordinarily challenging as computations are arduous and quantum-based molecular dynamics simulation times are limited to, at most, hundreds of ps. Here, the Extended Lagrangian Born-Oppenheimer molecular dynamics formalism is used in conjunction with Parallel Replica Dynamics to obtain an accurate tool to describe the long-term dynamics of reactive benzene. Langevin dynamics has been employed at different temperatures to calculate the first reaction times in a periodic benzene sample at different pressures. We have also studied the long-term behavior of vacancy complexes, which compare satisfactorily with experimental observations. Our coupled engine runs for times on the order of ns (two to three orders of magnitude longer than traditional techniques) and is capable of detecting reactions characterized by rates significantly lower than we could study before.