Theoretical studies on the properties and dynamics of electronic excited states
Thesis: S.B., Massachusetts Institute of Technology, Department of Chemistry, 2016.
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| Other Authors: | |
| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2016
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| Online Access: | http://hdl.handle.net/1721.1/105054 |
| _version_ | 1826190255729934336 |
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| author | Hait, Diptarka |
| author2 | Troy Van Voorhis. |
| author_facet | Troy Van Voorhis. Hait, Diptarka |
| author_sort | Hait, Diptarka |
| collection | MIT |
| description | Thesis: S.B., Massachusetts Institute of Technology, Department of Chemistry, 2016. |
| first_indexed | 2024-09-23T08:37:27Z |
| format | Thesis |
| id | mit-1721.1/105054 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T08:37:27Z |
| publishDate | 2016 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1050542019-04-09T18:50:15Z Theoretical studies on the properties and dynamics of electronic excited states Hait, Diptarka Troy Van Voorhis. Massachusetts Institute of Technology. Department of Chemistry. Massachusetts Institute of Technology. Department of Chemistry. Chemistry. Thesis: S.B., Massachusetts Institute of Technology, Department of Chemistry, 2016. Cataloged from PDF version of thesis. Includes bibliographical references (pages 101-106). Molecules are rarely found in electronic excited states under standard conditions but such states play a major role in chemical reactions. Computational prediction of properties of such states is hard with standard DFT protocols, as made evident by the failure of linear response TDDFT in predicting energies of charge-transfer excited states with semi-local functionals. Condensed phase dynamics of excited states are even more intractable on account of the computational cost scaling exponentially with the number of condensed phase particles under consideration. However, it is still possible to develop cheap but accurate approximations for properties and dynamics of excited states, and herein we describe some of the methods developed by us along those directions. We first demonstrate that restricted open shell Kohn-Sham (ROKS) calculations with semi-local hybrid functionals give good agreement with experimental absorption energies, emission energies, zero-zero transition energies and singlet-triplet gaps of CT states-unlike TDDFT, which significantly underestimates energy gaps. We then show that is possible to compute the effects of conical intersections on non-adiabatic dynamics of chemical systems by deriving perturbative memory kernels for the linear vibronic coupling model, and employing them to calculate the population dynamics of the Fe(II)-Fe(III) self-exchange reaction. Finally, we present a relationship between perturbation theory traces of the spin-boson model that allows us to obtain the exact solution with arbitrary initial harmonic bath state in the slow bath limit. We then attempt to generalize it to multiple states, and devise a similar trace relationship which makes it trivial to write down closed form expressions for populations and kernels to arbitrary order for any n level system. by Diptarka Hait. S.B. 2016-10-25T19:51:40Z 2016-10-25T19:51:40Z 2016 2016 Thesis http://hdl.handle.net/1721.1/105054 959715547 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 106 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Chemistry. Hait, Diptarka Theoretical studies on the properties and dynamics of electronic excited states |
| title | Theoretical studies on the properties and dynamics of electronic excited states |
| title_full | Theoretical studies on the properties and dynamics of electronic excited states |
| title_fullStr | Theoretical studies on the properties and dynamics of electronic excited states |
| title_full_unstemmed | Theoretical studies on the properties and dynamics of electronic excited states |
| title_short | Theoretical studies on the properties and dynamics of electronic excited states |
| title_sort | theoretical studies on the properties and dynamics of electronic excited states |
| topic | Chemistry. |
| url | http://hdl.handle.net/1721.1/105054 |
| work_keys_str_mv | AT haitdiptarka theoreticalstudiesonthepropertiesanddynamicsofelectronicexcitedstates |