The temperature-dependent hydrogen-bond geometry in liquid water was studied by x-ray Compton scattering using synchrotron radiation combined with density functional theory analysis (Hakala et al.). Systematic changes, related to the weakening of hydrogen bonding, were observed in the shape of the Compton profile upon increasing the temperature. Using model calculations and published distribution functions of hydrogen-bond geometries obtained from a NMR study a significant correlation between the hydrogen-bond length and angle was found. This imposes a new constraint on the possible local structure distributions in liquid water. In particular, the angular distortions of the short hydrogen bonds are significantly restricted.

Hakala M., Nygård K., Manninen S., Huotari S., Buslaps T., Nilsson A., Pettersson L.G.M., Hämäläinen K. - Correlation of hydrogen bond lengths and angles in liquid water based on Compton scattering - J. chem. phys. 125, 084504-1-084504-7 (2006).

a) Depth resolved residual macro-strains in longitudinal direction (parallel to weld); b) through thickness longitudinal residual stress component, calculated from the strain measurements in three dimensions; c) enlarged view of the distribution of the plate material (AA6082 and AA2024) in the stirring zone.