Efficient methods and practical guidelines for simulating isotope effects.
The shift in chemical equilibria due to isotope substitution is frequently exploited to obtain insight into a wide variety of chemical and physical processes. It is a purely quantum mechanical effect, which can be computed exactly using simulations based on the path integral formalism. Here we discu...
| Main Authors: | , |
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| Format: | Journal article |
| Language: | English |
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American Institute of Physics
2013
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| _version_ | 1826277655750639616 |
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| author | Ceriotti, M Markland, T |
| author_facet | Ceriotti, M Markland, T |
| author_sort | Ceriotti, M |
| collection | OXFORD |
| description | The shift in chemical equilibria due to isotope substitution is frequently exploited to obtain insight into a wide variety of chemical and physical processes. It is a purely quantum mechanical effect, which can be computed exactly using simulations based on the path integral formalism. Here we discuss how these techniques can be made dramatically more efficient, and how they ultimately outperform quasi-harmonic approximations to treat quantum liquids not only in terms of accuracy, but also in terms of computational cost. To achieve this goal we introduce path integral quantum mechanics estimators based on free energy perturbation, which enable the evaluation of isotope effects using only a single path integral molecular dynamics trajectory of the naturally abundant isotope. We use as an example the calculation of the free energy change associated with H/D and (16)O/(18)O substitutions in liquid water, and of the fractionation of those isotopes between the liquid and the vapor phase. In doing so, we demonstrate and discuss quantitatively the relative benefits of each approach, thereby providing a set of guidelines that should facilitate the choice of the most appropriate method in different, commonly encountered scenarios. The efficiency of the estimators we introduce and the analysis that we perform should in particular facilitate accurate ab initio calculation of isotope effects in condensed phase systems. |
| first_indexed | 2024-03-06T23:32:11Z |
| format | Journal article |
| id | oxford-uuid:6c6a7042-4db2-4aa4-9632-703f126f2037 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T23:32:11Z |
| publishDate | 2013 |
| publisher | American Institute of Physics |
| record_format | dspace |
| spelling | oxford-uuid:6c6a7042-4db2-4aa4-9632-703f126f20372022-03-26T19:10:42ZEfficient methods and practical guidelines for simulating isotope effects.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:6c6a7042-4db2-4aa4-9632-703f126f2037EnglishSymplectic Elements at OxfordAmerican Institute of Physics2013Ceriotti, MMarkland, TThe shift in chemical equilibria due to isotope substitution is frequently exploited to obtain insight into a wide variety of chemical and physical processes. It is a purely quantum mechanical effect, which can be computed exactly using simulations based on the path integral formalism. Here we discuss how these techniques can be made dramatically more efficient, and how they ultimately outperform quasi-harmonic approximations to treat quantum liquids not only in terms of accuracy, but also in terms of computational cost. To achieve this goal we introduce path integral quantum mechanics estimators based on free energy perturbation, which enable the evaluation of isotope effects using only a single path integral molecular dynamics trajectory of the naturally abundant isotope. We use as an example the calculation of the free energy change associated with H/D and (16)O/(18)O substitutions in liquid water, and of the fractionation of those isotopes between the liquid and the vapor phase. In doing so, we demonstrate and discuss quantitatively the relative benefits of each approach, thereby providing a set of guidelines that should facilitate the choice of the most appropriate method in different, commonly encountered scenarios. The efficiency of the estimators we introduce and the analysis that we perform should in particular facilitate accurate ab initio calculation of isotope effects in condensed phase systems. |
| spellingShingle | Ceriotti, M Markland, T Efficient methods and practical guidelines for simulating isotope effects. |
| title | Efficient methods and practical guidelines for simulating isotope effects. |
| title_full | Efficient methods and practical guidelines for simulating isotope effects. |
| title_fullStr | Efficient methods and practical guidelines for simulating isotope effects. |
| title_full_unstemmed | Efficient methods and practical guidelines for simulating isotope effects. |
| title_short | Efficient methods and practical guidelines for simulating isotope effects. |
| title_sort | efficient methods and practical guidelines for simulating isotope effects |
| work_keys_str_mv | AT ceriottim efficientmethodsandpracticalguidelinesforsimulatingisotopeeffects AT marklandt efficientmethodsandpracticalguidelinesforsimulatingisotopeeffects |