From the condition for invariance of the energy under rotations of the Jaco
bi coordinates, a relationship is obtained that relates the expected values
of combinations of degrees of interparticle separations in quantum-mechani
cal systems. This relationship, which is satisfied for atoms and molecules
with like particles identically, because of the permutational symmetry, is
an extremely sensitive criterion for the accuracy of the wave functions of
asymmetric systems, consisting of unlike particles and having no permutatio
nal symmetry. The application of this criterion is illustrated for the exam
ple of the asymmetric He-4 mu(-)e(-) mesoatom. (C) 2000 MAIK "Nauka/Interpe
riodica".