It is shown that the set of transformations of the s and d boson operators
that maintain the IBM-like form of the Hamiltonian comprises a discrete poi
nt symmetry group D-2.' The transformations manifest themselves as a parame
ter symmetry of the IBM-1 Hamiltonian. The transformations considered are a
lso necessary for constructing the most general IBM-2 Hamiltonian. The prop
erties of the potential energy surfaces arising in connection with these tr
ansformations are discussed. (C) 2000 MAIK "Nauka/lnterperiodica".