Classical Nuclear Motion: Comparison to Approaches with Quantum Mechanical Nuclear Motion
Ab initio molecular dynamics combines a classical description of nuclear motion with a density-functional description of the electronic cloud. This approach nicely describes chemical reactions. A possible conclusion is that a quantum mechanical description of nuclear motion is not needed. Using Occa...
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Format: | Article |
Language: | English |
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MDPI AG
2022-12-01
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Series: | Hydrogen |
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Online Access: | https://www.mdpi.com/2673-4141/4/1/2 |
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author | Irmgard Frank |
author_facet | Irmgard Frank |
author_sort | Irmgard Frank |
collection | DOAJ |
description | Ab initio molecular dynamics combines a classical description of nuclear motion with a density-functional description of the electronic cloud. This approach nicely describes chemical reactions. A possible conclusion is that a quantum mechanical description of nuclear motion is not needed. Using Occam’s razor, this means that, being the simpler approach, classical nuclear motion is preferable. In this paper, it is claimed that nuclear motion is classical, and this hypothesis will be tested in comparison to methods with quantum mechanical nuclear motion. In particular, we apply ab initio molecular dynamics to two photoreactions involving hydrogen. Hydrogen, as the lightest element, is often assumed to show quantum mechanical tunneling. We will see that the classical picture is fully sufficient. The quantum mechanical view leads to phenomena that are difficult to understand, such as the entanglement of nuclear motion. In contrast, it is easy to understand the simple classical picture which assumes that nuclear motion is steady and uniform unless a force is acting. Of course, such a hypothesis must be verified for many systems and phenomena, and this paper is one more step in this direction. |
first_indexed | 2024-03-11T06:28:17Z |
format | Article |
id | doaj.art-9d8bb296be3a4721afb6243816d8dfd8 |
institution | Directory Open Access Journal |
issn | 2673-4141 |
language | English |
last_indexed | 2024-03-11T06:28:17Z |
publishDate | 2022-12-01 |
publisher | MDPI AG |
record_format | Article |
series | Hydrogen |
spelling | doaj.art-9d8bb296be3a4721afb6243816d8dfd82023-11-17T11:25:36ZengMDPI AGHydrogen2673-41412022-12-0141112110.3390/hydrogen4010002Classical Nuclear Motion: Comparison to Approaches with Quantum Mechanical Nuclear MotionIrmgard Frank0Institute of Physical Chemistry and Electrochemistry, Theoretical Chemistry, Leibniz University of Hannover, Callinstr. 3A, 30167 Hannover, GermanyAb initio molecular dynamics combines a classical description of nuclear motion with a density-functional description of the electronic cloud. This approach nicely describes chemical reactions. A possible conclusion is that a quantum mechanical description of nuclear motion is not needed. Using Occam’s razor, this means that, being the simpler approach, classical nuclear motion is preferable. In this paper, it is claimed that nuclear motion is classical, and this hypothesis will be tested in comparison to methods with quantum mechanical nuclear motion. In particular, we apply ab initio molecular dynamics to two photoreactions involving hydrogen. Hydrogen, as the lightest element, is often assumed to show quantum mechanical tunneling. We will see that the classical picture is fully sufficient. The quantum mechanical view leads to phenomena that are difficult to understand, such as the entanglement of nuclear motion. In contrast, it is easy to understand the simple classical picture which assumes that nuclear motion is steady and uniform unless a force is acting. Of course, such a hypothesis must be verified for many systems and phenomena, and this paper is one more step in this direction.https://www.mdpi.com/2673-4141/4/1/2Car–Parrinello molecular dynamicschemical reactionsphotoreactionsclassical nuclear motion |
spellingShingle | Irmgard Frank Classical Nuclear Motion: Comparison to Approaches with Quantum Mechanical Nuclear Motion Hydrogen Car–Parrinello molecular dynamics chemical reactions photoreactions classical nuclear motion |
title | Classical Nuclear Motion: Comparison to Approaches with Quantum Mechanical Nuclear Motion |
title_full | Classical Nuclear Motion: Comparison to Approaches with Quantum Mechanical Nuclear Motion |
title_fullStr | Classical Nuclear Motion: Comparison to Approaches with Quantum Mechanical Nuclear Motion |
title_full_unstemmed | Classical Nuclear Motion: Comparison to Approaches with Quantum Mechanical Nuclear Motion |
title_short | Classical Nuclear Motion: Comparison to Approaches with Quantum Mechanical Nuclear Motion |
title_sort | classical nuclear motion comparison to approaches with quantum mechanical nuclear motion |
topic | Car–Parrinello molecular dynamics chemical reactions photoreactions classical nuclear motion |
url | https://www.mdpi.com/2673-4141/4/1/2 |
work_keys_str_mv | AT irmgardfrank classicalnuclearmotioncomparisontoapproacheswithquantummechanicalnuclearmotion |