Densities and refractive indices for the ternary mixture methanol/propan-1-ol/acetonitrile

► Study of the ternary mixture methanol/propan-1-ol/acetonitrile. ► Refractive indices and densities at 298.15 K. ► Excess properties modeled by Redlich-Kister and Cibulka equations. ► Thermodynamic approach to excess refractive indices applied to ternary mixtures. ► Structural effects identified and interpreted in binary and ternary systems.