Thermodynamic optimization of the (Na2OÂ +Â SiO2Â +Â NaFÂ +Â SiF4) reciprocal system using the Modified Quasichemical Model in the Quadruplet Approximation

► We model the Na2O-SiO2-NaF-SiF4 reciprocal system based on a comprehensive review of all available experimental data. ► The assessment includes Na2O-SiO2 and NaF-SiF4 binary systems. ► Improvements to the Modified Quasichemical Model in the Quadruplet Approximation are presented. ► The very strong short-range ordering among first-nearest and second-nearest neighbors in this system is reproduced. ► This work constitutes the first assessment for all compositions and temperatures of a reciprocal oxyfluoride system.