Diffusion in supercooled water to 300 MPa

Measurements of the self-diffusion coefficient in supercooled water to 300 MPa are reported. Translational diffusion in liquid water at 243 K is enhanced by 60% when the pressure is increased from 0.1 to 150 MPa, and rotational diffusion is enhanced by almost 250% between 0.1 and 250 MPa. These striking anomalies are interpreted in terms of the proximity of a conjectured line of spinodallike stability limits in the supercooled liquid