THE LOCAL BONDING IN WATER FROM -20-DEGREES-C TO 220-DEGREES-C

It is believed that the mean distance between water molecules increase s with a decrease in water temperature below room temperature due to t he increase in 'hydrogen bonds', which implies an increase in the loca l fourfold coordination. In order to investigate how far this effect e xtends over a wider range, we have made constant-density measurements of the principal peak of the neutron structure factor of heavy water a s a function of temperature. Data were taken at densities from 10% gre ater to 8% less than the maximum density at 1 atm, and for temperature s extending from -20 to 220-degrees-C. The effects seen at ambient con ditions were found to extend over this whole range.