Ring polymer molecular dynamics
<p>This thesis presents the ring polymer molecular dynamics (RPMD) approximation to the Kubo-transformed time correlation function and shows how it may be used as the basis of an approximate quantum-mechanical method for determining the dynamical properties of condensed-phase molecular system...
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| Формат: | Диссертация |
| Язык: | English |
| Опубликовано: |
2006
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| Предметы: |
| _version_ | 1826304876944031744 |
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| author | Craig, I Ian R. Craig |
| author2 | Manolopoulos, D |
| author_facet | Manolopoulos, D Craig, I Ian R. Craig |
| author_sort | Craig, I |
| collection | OXFORD |
| description | <p>This thesis presents the ring polymer molecular dynamics (RPMD) approximation to the Kubo-transformed time correlation function and shows how it may be used as the basis of an approximate quantum-mechanical method for determining the dynamical properties of condensed-phase molecular systems.</p> <p>The performance of the RPMD method is initially investigated by calculating the position (<em>q<sup>ˆ</sup></em>), and position-cubed (<em>q<sup>ˆ3</sup></em>), autocorrelation functions of a series of onedimensional potential wells of varying anharmonicity. It is then applied to the evaluation of the incoherent dynamic structure factors of liquid para-hydrogen at 14 K. Finally, the RPMD method is used to determine canonical rate coefficients for two onedimensional models of bimolecular chemical reactions and a multidimensional model of a solution-phase proton transfer reaction. For each application, the accuracy of the RPMD method is established by comparison with exact quantum-mechanical results and/or with experiment. Throughout this work, an emphasis is placed upon identifying the situations in which the RPMD approximation breaks down.</p> <p>It is found that the RPMD method is capable of providing an accurate approximation to the time correlation functions of a variety of condensed-phase molecular systems. Situations for which it is inaccurate include correlation functions which correlate highly nonlinear operators and those involving significant quantum interference effects in the real-time dynamics.</p> |
| first_indexed | 2024-03-07T06:24:22Z |
| format | Thesis |
| id | oxford-uuid:f3c37800-6fc7-4d8b-b135-94d94a7cf4e1 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:24:22Z |
| publishDate | 2006 |
| record_format | dspace |
| spelling | oxford-uuid:f3c37800-6fc7-4d8b-b135-94d94a7cf4e12022-03-27T12:14:31ZRing polymer molecular dynamicsThesishttp://purl.org/coar/resource_type/c_db06uuid:f3c37800-6fc7-4d8b-b135-94d94a7cf4e1Molecular dynamicsCondensed matterEnglishPolonsky Theses Digitisation Project2006Craig, IIan R. CraigManolopoulos, DManolopoulos, D<p>This thesis presents the ring polymer molecular dynamics (RPMD) approximation to the Kubo-transformed time correlation function and shows how it may be used as the basis of an approximate quantum-mechanical method for determining the dynamical properties of condensed-phase molecular systems.</p> <p>The performance of the RPMD method is initially investigated by calculating the position (<em>q<sup>ˆ</sup></em>), and position-cubed (<em>q<sup>ˆ3</sup></em>), autocorrelation functions of a series of onedimensional potential wells of varying anharmonicity. It is then applied to the evaluation of the incoherent dynamic structure factors of liquid para-hydrogen at 14 K. Finally, the RPMD method is used to determine canonical rate coefficients for two onedimensional models of bimolecular chemical reactions and a multidimensional model of a solution-phase proton transfer reaction. For each application, the accuracy of the RPMD method is established by comparison with exact quantum-mechanical results and/or with experiment. Throughout this work, an emphasis is placed upon identifying the situations in which the RPMD approximation breaks down.</p> <p>It is found that the RPMD method is capable of providing an accurate approximation to the time correlation functions of a variety of condensed-phase molecular systems. Situations for which it is inaccurate include correlation functions which correlate highly nonlinear operators and those involving significant quantum interference effects in the real-time dynamics.</p> |
| spellingShingle | Molecular dynamics Condensed matter Craig, I Ian R. Craig Ring polymer molecular dynamics |
| title | Ring polymer molecular dynamics |
| title_full | Ring polymer molecular dynamics |
| title_fullStr | Ring polymer molecular dynamics |
| title_full_unstemmed | Ring polymer molecular dynamics |
| title_short | Ring polymer molecular dynamics |
| title_sort | ring polymer molecular dynamics |
| topic | Molecular dynamics Condensed matter |
| work_keys_str_mv | AT craigi ringpolymermoleculardynamics AT ianrcraig ringpolymermoleculardynamics |