Fig. 6

The sc(i) → mc(i − 4) and mc(i) → mc(i − 4) hydrogen bonds are bifurcate. a Starting configuration used in the simulation, with the atoms included in the QM subsystem shown as sticks and the distances plot in b shown as dashed lines. b Time series of the distances between donor and acceptor for the mc(Q1) → mc(L1) and sc(Q1) → mc(L1) interactions, with an indication, in a gray background, of the frames for which 60° < χ³ < 120°. c Distributions of the χ¹, χ², and χ³ dihedral angles of the side chains of Q1 with an indication, as a gray shade, of the range of values of χ³ that are compatible with the sc(Q1) → mc(L1) hydrogen bond. d Distribution, plotted as a normalized histogram, of the electron density ρ(r) corresponding to the mc(Q1) → mc(L1) interaction (yellow) in the absence (white background) and in the presence (gray background) of the sc(Q1) → mc(L1) interaction and of the electron density corresponding to the sc(Q1) → mc(L1) interaction (purple) and bifurcate interactions (gray)