Comparison of the GEMC-simulated (black triangles) ()-diagram [6] for [bmim][BF₄] with the HPD-predicted coexistence of orthobaric densities (lines with black squares); the characteristic (, ) points are emphasized as well as the distinction of respective rectilinear [6] and strongly-curved (HPD) diameters. The input low-temperature experimental -data [1, 2] are represented by white diamonds. Location of classical spinodal and its critical point (□) predicted by LF-EOS [14] is shown by dashed line.