Recently, we presented arguments strongly supporting a type of mixture
model-actually, a mixed bonding model-for liquid water (H2O) through
an analysis of its extremely precise temperature-dependent density dat
a. This model is now applied to the densities of liquid D2O in the tem
perature range -20 to + 100 degrees C. It is found that the available
experimental data can be fit to the reported five-decimal-point precis
ion. As in the case of H2O, the output parameters indicate the existen
ce of two general types of bonding characteristics in the liquid, a bu
lky form similar to that in ice-Ih and a dense form such as that found
in ice-II. Independent support for the model is obtained from the tem
perature-differential X-ray scattering data of Bosio et al, on D2O.