The calculation of the semiclassical propagator is a Monte Carlo integration over classical trajectories. This can be accelerated either by importance sampling or by parallelization of the phase space integration. In the first case, a multiple coherent states time-averaging [1] semiclassical initial value representation (MC-TA-SC-IVR) method for spectra calculations is presented.[2, 3] The method is implemented for ab initio semiclassical simulations, i.e. a direct dynamics approach, and it is shown to faithfully reproduce all kind of quantum effects, including ZPEs, anharmonicities, tunneling splittings,[4] resonances [5] and vibrational eigenfunctions.[6] This on-the-fly approach is useful in particular for complex systems,[7, 8] where the elaboration of a pre-computed potential energy surface can turn into a formidable task. In the second case, SC-IVR is implemented for GPUs hardware. [9] An almost constant scaling for GPU calculations versus a linear scaling for CPU ones is found respect to the number of trajectories. Issues and limitations related to the GPU implementation will be discussed. [1] A. L. Kaledin and W. H. Miller, J. Chem. Phys. 118, 7174 (2003) [2] M. Ceotto, S. Atahan, S. Shim, G. F. Tantardini, and A. Aspuru-Guzik, Phys. Chem. Chem. Phys. 11, 3861 (2009) [3] M. Ceotto, S. Atahan, G. F. Tantardini, and A. Aspuru-Guzik, J. Chem. Phys. 130, 234113 (2009) [4] R. Conte, A. Aspuru-Guzik, and M. Ceotto, J. Phys. Chem. Lett. 4, 3407-3412 (2013) [5] M. Ceotto, D. Dell'Angelo, and G. F. Tantardini, J. Chem. Phys. 133, 054701 (2010) [6] M. Ceotto, S. Valleau, G. F. Tantardini, and A. Aspuru-Guzik, J. Chem Phys. 134, 234103 (2011) [7] M. Ceotto, G. F. Tantardini, and A. Aspuru-Guzik, J. Chem. Phys. 135, 214108 (2011) [8] M. Ceotto, Y. Zhuang, and W.L. Hase, J. Chem. Phys. 138, 054116 (2013) [9] D. Tamascelli, F. D'Ambrosio, R. Conte, and M. Ceotto, in progress

A General Purpose Implementations of Semiclassical Molecular Dynamics for CPU and GPU hardware / M. Ceotto. ((Intervento presentato al convegno EPFL Physical Chemistry Seminar tenutosi a Lausanne nel 2014.

A General Purpose Implementations of Semiclassical Molecular Dynamics for CPU and GPU hardware

M. Ceotto
2014

Abstract

The calculation of the semiclassical propagator is a Monte Carlo integration over classical trajectories. This can be accelerated either by importance sampling or by parallelization of the phase space integration. In the first case, a multiple coherent states time-averaging [1] semiclassical initial value representation (MC-TA-SC-IVR) method for spectra calculations is presented.[2, 3] The method is implemented for ab initio semiclassical simulations, i.e. a direct dynamics approach, and it is shown to faithfully reproduce all kind of quantum effects, including ZPEs, anharmonicities, tunneling splittings,[4] resonances [5] and vibrational eigenfunctions.[6] This on-the-fly approach is useful in particular for complex systems,[7, 8] where the elaboration of a pre-computed potential energy surface can turn into a formidable task. In the second case, SC-IVR is implemented for GPUs hardware. [9] An almost constant scaling for GPU calculations versus a linear scaling for CPU ones is found respect to the number of trajectories. Issues and limitations related to the GPU implementation will be discussed. [1] A. L. Kaledin and W. H. Miller, J. Chem. Phys. 118, 7174 (2003) [2] M. Ceotto, S. Atahan, S. Shim, G. F. Tantardini, and A. Aspuru-Guzik, Phys. Chem. Chem. Phys. 11, 3861 (2009) [3] M. Ceotto, S. Atahan, G. F. Tantardini, and A. Aspuru-Guzik, J. Chem. Phys. 130, 234113 (2009) [4] R. Conte, A. Aspuru-Guzik, and M. Ceotto, J. Phys. Chem. Lett. 4, 3407-3412 (2013) [5] M. Ceotto, D. Dell'Angelo, and G. F. Tantardini, J. Chem. Phys. 133, 054701 (2010) [6] M. Ceotto, S. Valleau, G. F. Tantardini, and A. Aspuru-Guzik, J. Chem Phys. 134, 234103 (2011) [7] M. Ceotto, G. F. Tantardini, and A. Aspuru-Guzik, J. Chem. Phys. 135, 214108 (2011) [8] M. Ceotto, Y. Zhuang, and W.L. Hase, J. Chem. Phys. 138, 054116 (2013) [9] D. Tamascelli, F. D'Ambrosio, R. Conte, and M. Ceotto, in progress
24-feb-2014
semiclassical molecular dynamics ; GPU
Settore CHIM/02 - Chimica Fisica
École polytechnique fédérale de Lausanne
A General Purpose Implementations of Semiclassical Molecular Dynamics for CPU and GPU hardware / M. Ceotto. ((Intervento presentato al convegno EPFL Physical Chemistry Seminar tenutosi a Lausanne nel 2014.
Conference Object
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/235257
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact