We extensively describe our recently established "divide-and-conquer" semiclassical method [M. Ceotto, G. Di Liberto, and R. Conte, Phys. Rev. Lett. 119, 010401 (2017)] and propose a new implementation of it to increase the accuracy of results. The technique permits us to perform spectroscopic calculations of high-dimensional systems by dividing the full-dimensional problem into a set of smaller dimensional ones. The partition procedure, originally based on a dynamical analysis of the Hessian matrix, is here more rigorously achieved through a hierarchical subspace-separation criterion based on Liouville's theorem. Comparisons of calculated vibrational frequencies to exact quantum ones for a set of molecules including benzene show that the new implementation performs better than the original one and that, on average, the loss in accuracy with respect to full-dimensional semiclassical calculations is reduced to only 10 wavenumbers. Furthermore, by investigating the challenging Zundel cation, we also demonstrate that the "divide-and-conquer" approach allows us to deal with complex strongly anharmonic molecular systems. Overall the method very much helps the assignment and physical interpretation of experimental IR spectra by providing accurate vibrational fundamentals and overtones decomposed into reduced dimensionality spectra.

"Divide and conquer" semiclassical molecular dynamics : A practical method for spectroscopic calculations of high dimensional molecular systems / G. Di Liberto, R. Conte, M. Ceotto. - In: THE JOURNAL OF CHEMICAL PHYSICS. - ISSN 0021-9606. - 148:1(2018 Jan 07). [10.1063/1.5010388]

"Divide and conquer" semiclassical molecular dynamics : A practical method for spectroscopic calculations of high dimensional molecular systems

G. Di Liberto
Primo
;
R. Conte
Secondo
;
M. Ceotto
Ultimo
2018

Abstract

We extensively describe our recently established "divide-and-conquer" semiclassical method [M. Ceotto, G. Di Liberto, and R. Conte, Phys. Rev. Lett. 119, 010401 (2017)] and propose a new implementation of it to increase the accuracy of results. The technique permits us to perform spectroscopic calculations of high-dimensional systems by dividing the full-dimensional problem into a set of smaller dimensional ones. The partition procedure, originally based on a dynamical analysis of the Hessian matrix, is here more rigorously achieved through a hierarchical subspace-separation criterion based on Liouville's theorem. Comparisons of calculated vibrational frequencies to exact quantum ones for a set of molecules including benzene show that the new implementation performs better than the original one and that, on average, the loss in accuracy with respect to full-dimensional semiclassical calculations is reduced to only 10 wavenumbers. Furthermore, by investigating the challenging Zundel cation, we also demonstrate that the "divide-and-conquer" approach allows us to deal with complex strongly anharmonic molecular systems. Overall the method very much helps the assignment and physical interpretation of experimental IR spectra by providing accurate vibrational fundamentals and overtones decomposed into reduced dimensionality spectra.
semiclassical
Settore CHIM/02 - Chimica Fisica
   Divide and Conquer ad initio semiclassical molecular dynamics for spectropic calculations of complex systems (SEMICOMPLEX)
   SEMICOMPLEX
   EUROPEAN COMMISSION
   H2020
   647107
7-gen-2018
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/544051
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