Abstract:The distributions of local structural units of calcium silicate melts were quantified by means of classical molecular dynamics simulation and a newly constructed structural thermodynamic model. The distribution of five kinds of Si-O tetrahedra Q_i from these two methods was compared with each other and also with the experimental Raman spectra, an excellent agreement was achieved. These not only displayed the panorama distribution of microstructural units in the whole composition range, but also proved that the thermodynamic model is suitable for the utilization as the subsequent application model of spectral experiments for the thermodynamic calculation. Meanwhile, the five refined regions mastered by different disproportionating reactions were obtained. Finally, the distributions of two kinds of connections between Q_i were obtained, denoted as Q_i-Ca-Q_j and Q_i-[O_b]-Q_j, from the thermodynamic model, and a theoretical verification was given that the dominant connections for any composition are equivalent connections.

Key words: distribution of microstructural units; molecular dynamic simulation; structural thermodynamic model; calcium silicate melts