N-formyl-L-prolinamide was subjected to geometry optimization at three levels of theory: HF/3-21G, HF/6-31G (d) and B3LYP/6-31G (d). At all three levels of computation the global minimum was γ(L) (inverse γ-Turn) backbone conformation with two ring-puckered forms 'UP' and 'DOWN'. At HF/3-21G level of theory three backbone conformations were found γ(L), ε(L), and α(L). At higher levels of theory the ε(L), and α(L) conformations disappeared. The 'UP' and 'DOWN' ring-puckered forms, in the γ(L) backbone conformation, led to practically identical vibrational spectra at the B3LYP/6-31G (d) level of theory.
- Molecular conformations
- Trans-Peptide bond
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry