ABINITIO CALCULATION OF THE DEUTERIUM QUADRUPOLE COUPLING IN LIQUID WATER

The quadrupole coupling constant and asymmetry parameter for the deuteron in liquid heavy water was determined using purely theoretical methods. Molecular-dynamics simulations with the ab initio potential-energy surface of Lie and Clementi were used to generate snapshots of the liquid. The electric-field gradient at the deuteron was then calculated for these configurations and averaged to obtain the liquid quadrupole coupling constant. At 300 K a quadrupole coupling constant of 256 +/- 5 kHz and an asymmetry parameter of 0.164 +/- 0.003 were obtained. The temperature dependence of the quadrupole coupling constant was investigated.