  We propose a new scheme to parameterize effective potentials that can be used
to simulate atomic systems such as oxide glasses. As input data for the
optimization, we use the radial distribution functions of the liquid and the
vibrational density of state of the glass, both obtained from ab-initio
simulations, as well as experimental data on the pressure dependence of the
density of the glass. For the case of silica, we find that this new scheme
facilitates finding pair potentials that are significantly more accurate than
previous ones even if the functional form is the same, thus demonstrating that
even simple two-body potentials can be superior to more complex three-body
potentials. We have tested the new potential by calculating the pressure
dependence of the elastic moduli and find a good agreement with the
corresponding experimental data.
