Exchange and correlation in molecular wire conductance: non-locality is the key
We study real-time electron dynamics in a molecular junction with a variety of approximations to the electronic structure, toward the ultimate aim of determining what ingredients are crucial for the accurate prediction of charge transport. We begin with real-time, all electron simulations using some...
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| Format: | Article |
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American Institute of Physics
2012
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| Online Access: | http://hdl.handle.net/1721.1/69813 https://orcid.org/0000-0001-7111-0176 |
| _version_ | 1811088244337541120 |
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| author | Evans, Jeremy S. Vydrov, Oleg A. Van Voorhis, Troy |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Evans, Jeremy S. Vydrov, Oleg A. Van Voorhis, Troy |
| author_sort | Evans, Jeremy S. |
| collection | MIT |
| description | We study real-time electron dynamics in a molecular junction with a variety of approximations to the electronic structure, toward the ultimate aim of determining what ingredients are crucial for the accurate prediction of charge transport. We begin with real-time, all electron simulations using some common density functionals that differ in how they treat long-range Hartree–Fock exchange. We find that the inclusion or exclusion of nonlocal exchange is the dominant factor determining the transport behavior, with all semilocal contributions having a smaller effect. In order to study nonlocal correlation, we first map our junction onto a simple Pariser–Parr–Pople (PPP) model Hamiltonian. The PPP dynamics are shown to faithfully reproduce the all electron results, and we demonstrate that nonlocal correlation can be readily included in the model space using the generator coordinate method (GCM). Our PPP-GCM simulations suggest that nonlocal correlation has a significant impact on the I-V character that is not captured even qualitatively by any of the common semilocal approximations to exchange and correlation. The implications of our results for transport calculations are discussed. |
| first_indexed | 2024-09-23T13:58:59Z |
| format | Article |
| id | mit-1721.1/69813 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T13:58:59Z |
| publishDate | 2012 |
| publisher | American Institute of Physics |
| record_format | dspace |
| spelling | mit-1721.1/698132022-09-28T17:31:00Z Exchange and correlation in molecular wire conductance: non-locality is the key Evans, Jeremy S. Vydrov, Oleg A. Van Voorhis, Troy Massachusetts Institute of Technology. Department of Chemistry Van Voorhis, Troy Evans, Jeremy S. Vydrov, Oleg A. Van Voorhis, Troy We study real-time electron dynamics in a molecular junction with a variety of approximations to the electronic structure, toward the ultimate aim of determining what ingredients are crucial for the accurate prediction of charge transport. We begin with real-time, all electron simulations using some common density functionals that differ in how they treat long-range Hartree–Fock exchange. We find that the inclusion or exclusion of nonlocal exchange is the dominant factor determining the transport behavior, with all semilocal contributions having a smaller effect. In order to study nonlocal correlation, we first map our junction onto a simple Pariser–Parr–Pople (PPP) model Hamiltonian. The PPP dynamics are shown to faithfully reproduce the all electron results, and we demonstrate that nonlocal correlation can be readily included in the model space using the generator coordinate method (GCM). Our PPP-GCM simulations suggest that nonlocal correlation has a significant impact on the I-V character that is not captured even qualitatively by any of the common semilocal approximations to exchange and correlation. The implications of our results for transport calculations are discussed. National Science Foundation (U.S.) (CAREER under Grant No. CHE-0547877) David & Lucile Packard Foundation (Fellowship) 2012-03-16T16:23:06Z 2012-03-16T16:23:06Z 2009-07 2009-03 Article http://purl.org/eprint/type/JournalArticle 0021-9606 1089-7690 http://hdl.handle.net/1721.1/69813 Evans, Jeremy S., Oleg A. Vydrov, and Troy Van Voorhis. “Exchange and Correlation in Molecular Wire Conductance: Nonlocality Is the Key.” The Journal of Chemical Physics 131.3 (2009): 034106. https://orcid.org/0000-0001-7111-0176 en_US http://dx.doi.org/10.1063/1.3179754 Journal of Chemical Physics Creative Commons Attribution-Noncommercial-Share Alike 3.0 http://creativecommons.org/licenses/by-nc-sa/3.0/ application/pdf American Institute of Physics Prof. Van Voorhis via Erja Kajosalo |
| spellingShingle | Evans, Jeremy S. Vydrov, Oleg A. Van Voorhis, Troy Exchange and correlation in molecular wire conductance: non-locality is the key |
| title | Exchange and correlation in molecular wire conductance: non-locality is the key |
| title_full | Exchange and correlation in molecular wire conductance: non-locality is the key |
| title_fullStr | Exchange and correlation in molecular wire conductance: non-locality is the key |
| title_full_unstemmed | Exchange and correlation in molecular wire conductance: non-locality is the key |
| title_short | Exchange and correlation in molecular wire conductance: non-locality is the key |
| title_sort | exchange and correlation in molecular wire conductance non locality is the key |
| url | http://hdl.handle.net/1721.1/69813 https://orcid.org/0000-0001-7111-0176 |
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