Simulation of coherent energy transfer in a hydrogen bonded amide chain by Fermi resonance

Classical simulations are used to examine vibrational energy redistribution in a chain of hydrogen bonded N-methylacetamide molecules following excitation of a NH stretching mode or Amide-I mode at one end of the chain. The dynamics take place on a complex potential energy surface constructed from ab initio calculations and empirical surfaces, refined with reference to observed vibrational frequencies. Simulations are used to characterize the dynamical effects of variation of several important potential parameters, and to determine the existence of coherent energy transfer by Fermi resonance mechanisms. Results are discussed with reference to simple models.