O(5) Bases for Nuclear Seniority Model

Two complete sets of bases are given for the general representation of O(5), utilizing the SU(2) subgroup which classifies nuclear seniority model states. The first set, which are analogous to the $\text{SU(3)⊃O(3)}$ states of Elliott and Harvey, are formed by projecting good SU(2) states out of certain ``intrinsic'' states. The second set are analogous to the $\text{SU(3)⊃O(3)}$ states defined by Moshinsky and Bargmann; each state is characterized by a particular simple term which appears in the expansion of that state and no other. Transformation matrices between the two sets of states are given. The utility of the states for the calculation of generator matrix elements and Clebsch‐Gordan coefficients is discussed. The seniority model states of Hecht and Parikh are discussed briefly.