Quantum mechanical molecular dynamics of liquid water - SCC-DFTBmethod reparametrized

The SCC-DFTB is an approximate DFT method that permit to perform large scale calculations quantummechanically. Recently we have developed a method to automatize the parameterization of the SCC-DFTB. Born-Oppenheimer Molecular Dynamics (BOMD) at the SCC-DFTB potential energy surface has been envisaged to describe chemical systems that the water is a reactant such as water/metal oxides interfaces. The SCC-DFTB parameters for water was initially obtained by the FASP[1] program and refined using the Reverse Monte Carlo approach[2] using the following thermal equation, where ghH(r) and g~i are the Radial Distribution Function (RDF) of the 0-X (X = H, 0) from SCC-DFTB calculations and experiment, respectively; E~ep is the ith SCC-DFTB repulsion energy, k 8 is the Boltzmann constant and T is the temperature; E~~J is the corrected repulsion. The RDFs for 0-0 and 0-H are shown at Figure 1. The experimental 0-H and 0-0 RDF were obtained from the RMC method and a 0-0 benchmark from references [3] and [4], respectively. The results are in very good agreement with the experimental data [3,4]. The geometrical and dynamic properties of the water in different temperatures will be presented and discussed in details. Preliminary results concerning the water/solid interface will be briefly presented.