A molecular dynamics study of B2O3 glass using different interaction potentials

Molecular dynamics calculations of B2O3 glass were carried out, using seven different interaction potential schemes. Two-body Born-Mayer-Huggins potentials and in some samples a[so three-body bond-angle interactions were applied. Structural and dynamical properties of the simulated systems were evaluated and compared with experimental neutron diffraction, X-ray, Raman and infrared data. The structural characteristics of the samples are not very sensitive to the interaction potentials: in all cases, a continuous random network glass structure without any boroxol rings is generated. Experimental structural data are reproduced reasonably well. The dynamical behaviour of the glasses depends on both two- and three-body potentials. The two-body potentials, taken from literature, were reduced in order to obtain correct vibrational frequencies by multiplying all interaction potentials with a constant factor. Three-body interactions appear to be necessary for a satisfactory simulation of all vibrational modes in the glass network. Many features in the experimental spectra are reproduced surprisingly well.