Fig. 3.
Probability density of cos(θC-O-H) in the proximal hemispherical solvation shell around the terminal carbon atoms (water O within a C-O separation 1.5 Å beyond the most probable) for the different states, where θC-O-H is the angle between the vectors C → O and O → H. Hence the cosine is +1 if the O-H is pointed away from the terminal C and is -1 if the vector points toward terminal C. There are two peaks—one at cos(θC-O-H) ∼ 1 (acute angle peak) and the other at cos(θC-O-H) ∼ -0.44 (obtuse angle peak). The distribution for each state i is shifted vertically by 0.5i for clarity.