Viscosity and viscosity anomalies of model silicates and magmas: A numerical investigation

摘要: Abstract We present results for transport properties (diffusion and viscosity) using computer simulations. Focus is made on a densified binary sodium disilicate 2SiO 2 –Na O (NS2) liquid multicomponent magmatic liquids (MORB, basalt). In the NS2 liquid, show that certain number of anomalies appear when system densified: diffusivity maxima/minima found network-forming ions (Si,O) which bears some striking similarities with well-known case water or silica, whereas atom displays three distinct regimes diffusion. Some these features can be correlated obtained viscosity anomaly under pressure, latter being fairly well reproduced from simulated diffusion constant. model magmas (MORB liquid), we find plateau followed by continuous increase pressure. Finally, having computed both independently, discuss validity Eyring equation relates viscosity. It shown it considered as valid in melts high On overall, highlight difficulty establishing firm relationship between dynamics, structure thermodynamics complex liquids.