Vibrational energy transfer of the amide I mode of N-methylacetamide (NMA) is studied theoretically using the vibrational configuration interaction method. A quartic force field of NMA is constructed at the B3LYP/6-31G+(d) level of theory and its accuarcy is checked by comparing the resulting anharmonic frequencies with available theoretical and experimental values. Quantum dynamics calculations for the amide I mode excitation clarify the dominant energy transfer pathways, which sensitively depend on the anharmonic couplings among vibrational modes. A ratio of the anharmonic coupling to the frequency mismatch is employed to predict and interpret the dominant energy flow pathways.
Cite
@article{arxiv.0706.1905,
title = {Quantum dynamics of N-methylacetamide studied by the vibrational configuration interaction method},
author = {Hiroshi Fujisaki and Kiyoshi Yagi and Kimihiko Hirao and John E. Straub},
journal= {arXiv preprint arXiv:0706.1905},
year = {2009}
}