Comparison of X-Ray Diffraction Curves of Water and Deuterium Oxide at 25 degrees C

The difference in freezing point temperatures, maximum densities and molecular volumes and other physical constants of water and deuterium oxide indicate that the molecular forces do not remain entirely invariant with the isotopic change in mass. A comparison of the diffraction of x-ray curves for the two substances at 25 degrees C indicates that the liquid structure of deuterium oxide is much like that of water. The peaks in the deuterium oxide curve are slightly sharper, apparently explicable in the fact that, at 25 degrees C, this substance, compared with water, is nearer to its freezing point.