A complete critical evaluation of all available phase diagrath and thermodynamic data has been performed for all condensed phases of the CH3COOLi-CH3COOK-CH3COOCs system, and optimized model parameters have been found which best reproduce all available experimental data simultaneously. The CH3COOLi-CH3COOK-CH3COOCs system may be used in supported molten salt catalysis. The Modified Quasichemical Model for short-range ordering was used for the molten salt phase. No ternary model parameters were required for the liquid phase; the optimized binary parameters suffice to reproduce satisfactorily the available experimental data for the ternary system using a standard symmetric interpolation method. The calculated (predicted) minimum liquidus temperature corresponds to a ternary eutectic at T=368 K, with a liquid composition of (22.4 mol% CH3COOLi+32.3mol%CH3COOK+45.3mol%CH3COOCs). This relatively low liquidus temperature makes the ternary mixture an interesting alternative to ionic liquids. (C) 2015 Elsevier B.V. All rights reserved.