Dielectric and vibrational properties of amino acids

Tulip, P.R.; Clark, S.J.

Abstract

We calculate polarizabilitytensors and normal mode frequencies for the amino acids alanine, leucine, isoleucine, and valine using density functionalperturbation theory implemented within the plane wave pseudopotential framework. It is found that the behavior of the electron density under external fields depends to a large extent on the geometrical structure of the molecule in question, rather than simply on the constituent functional groups. The normal modes are able to help distinguish between the different types of intramolecular hydrogen bonding present, and help to explain why leucine is found in the zwitterionic form for the gaseous phase. Calculated IR spectra show a marked difference between those obtained for zwitterionic and nonzwitterionic molecules. These differences can be attributed to the different chemical and hydrogen bonds present. Effective dynamical charges are calculated, and compared to atomic charges obtained from Mulliken population analysis. It is found that disagreement exists, largely due to the differing origins of these quantities.

Citation

Tulip, P., & Clark, S. (2004). Dielectric and vibrational properties of amino acids. The Journal of Chemical Physics, 121(11), 5201-5210. https://doi.org/10.1063/1.1781615

• Journal Article Type: Article
• Acceptance Date: Jun 18, 2004
• Publication Date: Sep 15, 2004
• Deposit Date: Jan 31, 2012
• Publicly Available Date: Aug 18, 2015
• Journal: Journal of Chemical Physics
• Print ISSN: 0021-9606
• Electronic ISSN: 1089-7690
• Publisher: American Institute of Physics
• Peer Reviewed: Peer Reviewed
• Volume: 121
• Issue: 11
• Pages: 5201-5210
• DOI: https://doi.org/10.1063/1.1781615
• Public URL: https://durham-repository.worktribe.com/output/1486702