Principles of group-theoretical statistical mechanics

Three principles are presented as the basis for group-theoretical statistical mechanics (GTSM), incorporating Neumann's (or Curie's) principle as the first. The second extends Neumann's principle to molecule fixed axes, (x,y,z), as defined in molecular point-group theory, and the third deals with the symmetry of applied fields and their effect on molecular ensembles in the field-on steady state. The power of GTSM is illustrated with reference to the set of field-induced n-time correlation functions in the laboratory frame (X,Y,Z) and frame (x,y,z).