Alternative universality for a NAC multicritical point topology

An alternative universal description of the topology of NAC (nematic-smectic A-smectic C) multicritical points is suggested. In this approach, the NA and AC transition lines have the same critical exponents φNA = φAC = 0.67 ± 0.03, while the NC line critical exponent φNC is different. It appears that φNC is equal to 0.87 ± 0.04, which is close to the exponent for the dependence of the NC latent heat upon the proximity to the NAC point.