Sarah MAW (Univ. Manchester), Hirofumi SATO, Seiichiro TEN-NO and Fumio HIRATA
[Chem. Phys. Lett. 276, 20 (1997)]
We proposed a theoretical study of liquid water based on the coupled ab initio electronic structure theory and the integral equation method of liquids. The effective atomic charges of a water molecule determined from the ab initio method in liquid were greater by about twenty percent than the corresponding empirical parameters for the SPC and TIP3P models due essentially to the use of insufficient basis sets. The effective charge monotonically decreased with increasing temperature. The behavior was attributed to the decreased anisotropy of the electrostatic field due to the increased molecular rotation. The free energy was decreased monotonically with temperature. The behavior is in qualitative accord with experiments.