Abstract:Molecular dynamics simulations of the xCaO-(1-x)SiO₂ melts (x varying with the composition of melt) were performed to achieve some structural information. It is found that the first peak positions of Si-Si, Si-O and O-O partial radial distribution functions RDFs(3.165, 1.612 and 2.6 )agree very well with those of x-ray diffraction experiments. The discovered relation of coordinate number N_Si-Si(r₀) with the molar ratio of CaO is linear and the slope is -0.05617. The average bond lengths of Si-O_b and Si-O_nb are 1.6275~1.630 and 1.595~1.60, respectively. Both distribution curves of the angles O-Si-O and Si-O-Si show one peak. For the distribution of angle O-Si-O the positions of the peaks are just a little less than the typical tetrahedral angle 109.5°. And for angle Si-O-Si the positions of peaks fluctuate in the range from 148° to 151°. At last, the distribution of five Si-O tetrahedra was obtained and discussed.

Key words:  MD simulation, structural properties, CaO-SiO₂ melts