A computationally less demanding charge-on-spring model for the water molecule.
We developed a new charge-on-spring model for the water molecule with the advantage of being computationally less demanding. We start from the basic geometry of Lamoureux et al. [J. Chem. Phys. 119, 5185 (2003); Chem. Phys. Lett. 418, 245 (2006)] in order to have a good approximation for the quadrupole moment of the gas phase molecule, but we use only four charged sites. We polarize the molecules in two steps. First, the three sites of the equilibrium gas phase molecule are polarized and this process is accompanied by a charge rearrangement. This step creates the massless spring particle connected to the uncharged oxygen atom. The equilibrium position of the spring particle is found by iteration. We describe the construction of the model and present details of the results obtained by molecular dynamics simulation for the properties of liquid water, hexagonal ice, and gas clusters. Our results are comparable in quality to that of Lamoureux et al. [Chem. Phys. Lett. 418, 245 (2006)] and show good agreements with experiments.
Baranyai
András
A
Institute of Chemistry, Eötvös University, P.O. Box 32, Budapest 1518 112, Hungary. bajtony@chem.elte.hu