Study on conductivity property of quartz based on molecular simulation

In quartz system, conductivity property, to a great extent, depends on defects, including intrinsic and extrinsic defects. In this paper, we introduce the different defects into quartz system. And then defect formation energies are calculated based on density functional theory. From the computed results, the positions and concentration of defects in quartz can be obtained. We also apply the molecular dynamics simulation to calculate dynamics properties for these different defects models. In the molecular dynamics, different forcefields are utilized to compute the dynamics property of these defects systems. Dissimilar results are obtained, however, by these different forcefields. Comparing the simulated results, we choose the most suitable forcefield for quartz system. Finally, conductivity of quartz in defects systems can be obtained accurately. From the calculated result, we can find that Na atom plays the dominant role for conductivity. The simulation results are consistent with experiment data well. And the molecular simulate research can help establish relationship between microcosmic structure and macroscopic property.