A comment on the chain subduction criterion

Abstract

It is shown, by considering an example, that the chain subduction criterion (including the conventional group-theoretical criteria) considered by Jaric and Birman (see Phys. Rev. B, vol.16, p.2564, 1977) is not equivalent to the original Landau thermodynamic approach for the lower-symmetry phases occurring at continuous phase transitions. The authors argue that a procedure to replace the Landau thermodynamic method should be based on the use of Ascher's maximality principle, together with further restrictions coming from the minimisation of the thermodynamic potential.