14,997 research outputs found
Semiclassical vibrational spectroscopy : the importance of quantum anharmonicity in supra-molecular systems
No full textSemiclassical (SC) vibrational spectroscopy has been applied successfully to several molecular systems thanks to the possibility to regain quantum effects accurately starting from short-time classical trajectories.[1-5] Larger molecular and supra-molecular systems represent instead an open challenge in the field of semiclassical spectroscopy mainly due to the necessity to work in very high dimensionality.
To start off the talk I will present some recent theoretical advances able to extend the range of applicability of SC vibrational spectroscopy to very high-dimensional systems.[6-7] Then, I will move to applications of semiclassical spectroscopy concerning the vibrational features of water clusters and two supra-molecular systems involving glycine.[8-9] These applications will point out the importance of a multi-reference, dynamical approach able to reproduce quantum anharmonicities without employing any ad-hoc scaling factor.
[1] M. F. Herman, E. Kluk, Chem. Phys. 1984, 91, 27.
[2] A. L. Kaledin, W. H. Miller, J. Chem. Phys. 2003, 118, 7174.
[3] M. Ceotto, S. Atahan, G. F. Tantardini, A. Aspuru-Guzik, J. Chem. Phys. 2009, 130, 234113.
[4] R. Conte, A. Aspuru-Guzik, M. Ceotto, J. Phys. Chem. Lett. 2013, 4, 3407.
[5] F. Gabas, R. Conte, M. Ceotto, J. Chem. Theory Comput. 2017, 13, 2378.
[6] M. Ceotto, G. Di Liberto, R. Conte, Phys. Rev. Lett. 2017, 119, 010401.
[7] G. Di Liberto, R. Conte, M. Ceotto, J. Chem. Phys. 2018, 148, 014307.
[8] G. Di Liberto, R. Conte, M. Ceotto, J. Chem. Phys. 2018, 148, 104302.
[9] F. Gabas, G. Di Liberto, R. Conte, M. Ceotto, to be submitted
Accademia Pontaniana, Accademia di Scienze Morali e Politiche, Conferenze Congiunte dell’Anno Accademico 2019
No full textOpere del conte Algarotti.
No full textIncludes index in vol. 7.Added t.p. in vol. 1, engraved by Giuseppe Patrini. Engraved portrait medallion of the author on t.p. in vol. 1, small woodcut title-vignettes on title pages in vol. 2-10.Mode of access: Internet
Semiclassical Molecular Dynamics for Spectroscopic Calculations of Complex Systems
No full textI will present some novel semiclassical methods for spectroscopic calculations. These approaches can be employed for spectroscopic calculations of gas-phase molecular and supramolecular systems
up to hundreds of degrees of freedom, as well as to condensed phase systems. Some methods are based on a “divide-and-conquer” approach, where the full dimensional spectra are obtained as a
composition of several lower dimensional ones. Others exploit hierarchically the different levels of accuracy of different semiclassical propagators. For instance, in a system-bath problem lower
semiclassical accuracy is dedicated to the bath, while the system is treated with higher accuracy and the system spectrum is eventually singled out.
All methods are amenable for ab initio molecular dynamics simulations.
References
1. F. Gabas, G. Di Liberto, R. Conte, and M. Ceotto, Chemical Science 9 (41), 7885-8026 (2018);
2. X. Ma, G. Di Liberto, R. Conte, W. L. Hase, and M. Ceotto, JCP 149, 164113 (2018)
3. M. Micciarelli, R. Conte, J. Suarez, and M. Ceotto, JCP 149, 064115 (2018);
4. M. Buchholz, F. Grossmann, and M. Ceotto, JCP 148, 114107 (2018);
5. G. Di Liberto, R. Conte, and M. Ceotto, JCP 148, 104302 (2018);
6. G. Di Liberto, R. Conte, and M. Ceotto, JCP 148, 014307 (2018);
7. M. Buchholz, F. Grossmann, and M. Ceotto, JCP 147, 164110 (2017);
8. M. Ceotto, G. Di Liberto, and R. Conte, PRL 119, 010401 (2017);
9. F. Gabas, R. Conte, and M. Ceotto, JCTC 13, 2378-2388 (2017);
10. G. Di Liberto, M. Ceotto, JCP 145, 144107 (2016);
11. M. Buchholz, F. Grossmann, M. Ceotto, JCP 144, 094102 (2016)
Quantum Mechanical Methods for Spectroscopic Calculations of High Dimensional Molecular Systems
No full textI will present some novel semiclassical methods for spectroscopic calculations. These approaches can be employed for spectroscopic calculations of gas-phase molecular and supramolecular systems
up to hundreds of degrees of freedom, as well as to condensed phase systems. Some methods are based on a “divide-and-conquer” approach, where the full dimensional spectra are obtained as a
composition of several lower dimensional ones. Others exploit hierarchically the different levels of accuracy of different semiclassical propagators.
All methods are amenable to ab initio molecular dynamics simulations.
References
1. M. Micciarelli, R. Conte, J. Suarez, and M. Ceotto, JCP 149, 064115 (2018);
2. M. Buchholz, F. Grossmann, and M. Ceotto, JCP 148, 114107 (2018);
3. G. Di Liberto, R. Conte, and M. Ceotto, JCP 148, 104302 (2018);
4. G. Di Liberto, R. Conte, and M. Ceotto, JCP 148, 014307 (2018);
5. M. Buchholz, F. Grossmann, and M. Ceotto, JCP 147, 164110 (2017);
6. M. Ceotto, G. Di Liberto, and R. Conte, PRL 119, 010401 (2017);
7. F. Gabas, R. Conte, and M. Ceotto, JCTC 13, 2378-2388 (2017);
8. G. Di Liberto, M. Ceotto, JCP 145, 144107 (2016);
9. M. Buchholz, F. Grossmann, M. Ceotto, JCP 144, 094102 (2016)
Novel agents for microdispersed systems. Part II: new monodisperse F-alkylated sufactants with a polynerizable moiety
No full textIn this paper we describe a method of synthesis which allows one to obtain non ionic F-alkylated sufactants with a lateral polymerizable moiety and having a general formula analogous to non plymerizable non ionic F-alkylated surfactants by formally grafting a polymerizable group on the last ethylene oxide unit of a monodisperse polyoxyethylated F-alkylated surfactant
Investigating molecular quantum vibrational frequencies with semiclassical dynamics: theory and application to systems of astrochemical interest
No full textSemiclassical (SC) dynamics allows to regain quantum effects starting from short-time classical trajectories. This feature makes it an attractive and promising tool for accurate spectroscopy investigations, which cannot neglect quantum effects. To start off I will briefly review the main SC approaches employed in vibrational spectroscopy including very recent advances to extend the range of applicability of SC dynamics to large molecular and supra-molecular systems.[1-6] Then, I will present an application of the SC theory to the astrochemically relevant glycine molecule.[7] Finally, the semiclassical study of supra-molecular systems involving glycine will demonstrate the importance in vibrational spectroscopy of an approach able to account for quantum anharmonicity over the commonly employed procedures based on an ad hoc scaling of the harmonic frequencies.
1. M. F. Herman and E. Kluk, Chem. Phys. 91, 27 (1984).
2. A. L. Kaledin and W. H. Miller, J. Chem. Phys. 118, 7174 (2003).
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 (2013).
5. M. Ceotto, G. Di Liberto, and R. Conte, Phys. Rev. Lett. 119, 010401 (2017).
6. G. Di Liberto, R. Conte, and M. Ceotto, J. Chem. Phys. 148, 014307 (2018).
7. F. Gabas, R. Conte, and M. Ceotto, J. Chem. Theory Comput. 13, 2378 (2017)
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