Ramchandran plot / Ramachandran diagram / Ø, ψ plot
Developed by: G.N. Ramachandran in 1963 + and – + and + – and – 0 White regions: sterically disallowed for all amino acids except glycine Red regions: allowed regions namely the alpha-helical and beta-helical conformations Yellow areas: outer limit Exception: Glycine can lie anywhere