For these two tetrafluorides, 1 and 2, the equivalence of the B-atoms results in the symmetry properties of the PESs recapitulating the symmetries of the configurations space. This is, however, not a general property of analogous PESs constructed from arbitrary combinations of vibrational normal modes. It occurs here as all chemical entities with configurations comprising this AB4 T-4 E-mode configuration space exhibit at least global molecular D2 symmetry (i.e., all possible B-atom pairs and bond lengths are symmetric).