10.1021/acs.jpcb.5b11643.s001 Kaicong Cai Kaicong Cai Fenfen Du Fenfen Du Xuan Zheng Xuan Zheng Jia Liu Jia Liu Renhui Zheng Renhui Zheng Juan Zhao Juan Zhao Jianping Wang Jianping Wang General Applicable Frequency Map for the Amide‑I Mode in β‑Peptides American Chemical Society 2016 GA map works frequency force fields General Applicable Frequency Map peptide NEPA solute interaction vibrational 2016-02-09 12:09:41 Journal contribution https://acs.figshare.com/articles/journal_contribution/General_Applicable_Frequency_Map_for_the_Amide_I_Mode_in_Peptides/2075650 In this work, a general applicable amide-I vibrational frequency map (GA map) for β-peptides in a number of common solvents was constructed, based on a peptide derivative, <i>N</i>-ethylpropionamide (NEPA). The map utilizes force fields at the ab initio computational level to accurately describe molecular structure and solute–solvent interactions, and also force fields at the molecular mechanics level to take into account long-range solute–solvent interactions. The results indicate that the GA map works reasonably for mapping the vibrational frequencies of the amide-I local-modes for β-peptides, holding promises for understanding the complicated infrared spectra of the amide-I mode in β-polypeptides.