THE STRUCTURE OF RAREFIED AND DENSIFIED PbSiO3 GLASS: A MOLECULAR DYNAMICS STUDY

Abstract

The paper is a molecular dynamics (MD) study of the structure of rarefied and densified lead-silicate glass of the PbSiO₃ composition. Simulations have been performed in the constant volume regime for systems with densities of 3 000, 4 000, 5 000, 5 970 (normal density), 7 000 and 8 000 kg/m³, using a two-body potential (Born-Mayer repulsive forces and Coulomb forces due to full ionic charges). All the systems were initially prepared as well equilibrated hot melts, and then slowly cooled down to 300K. The information on short-range correlations was obtained in a conventional way (from radial and angular distribution functions), while the middle-range order was studied via cation-anion ring analysis, using our new programme for basal ring determination. The structure of rarefied and densified glasses is compared with the structure of the same glasses under normal conditions. Moreover, the present results on PbSiO₃ glass are compared with the corresponding data previously obtained for rarefied and densified PbGeO₃ glass (Rybicki et al. 2001 Comput. Met. Sci. Tech. 7 91–112).