English: Backbone-conformation dependent interactions occur between gamma heavy atoms (C_γ,O_γ,O_γ1,C_γ1,C_γ2,S_γ) and backbone C_i-1 (carbonyl carbon of the previous amino acid), backbone N_i+1 (backbone nitrogen of the next amino acid), backbone O_i (backbone oxygen of the same amino acid), and the hydrogen bond donor to backbone N_i of the same amino acid ("hb" below, assuming linear hydrogen bond between oxygen and H-N bond). These interactions are expected to be strongly repulsive when dihedral angles connecting these heavy atoms to gamma heavy atoms occur in +60°,-60° or -60°,+60° pairs. They will occur in a range about the φ and ψ dihedrals that cause the connecting dihedrals to the backbone to be near +60° or -60° (when connecting dihedral to X_γ is -60° or +60° respectively). In each case, the dihedrals needed are of the form: X₁-X₂-X₃-X₄ and X₂-X₃-X₄-X₅. So for instance for ψ dependent interactions, the dihedrals are N_i+1-C-C_α-C_β and C-C_α-C_β-X_γ or ψ+120° and χ₁-120° respectively. Interactions with "hb" are expected to be weak, but the backbone-dependent rotamer library does exhibit effects due to this interaction.