Symmetry-adapted bases over Liouville space
Francis P. Temme
The irreducible representation under for spin clusters of identical Ii ≥ 1 spin systems are explicitly derived over |IMα> Hilbert space for the range of F z subspaces by using the combinatorial aspects of each ‘weight’ set (M 1 – M 4). This defines the invariance properties for each specific Fz , and consequently for the complete system over ∑Fz . Our investigations show that there are limiting , i.e. independent of Ii , for Fz > Izi for integer spins, or Fz > 2Izi , for half integer spins. Similar considerations apply to the irreducible representations that characterize like ki - | kqv≫ Liouville space for q > (k max – ki ), where k and ki refer to the tensor ranks of the total system and the Ii spin, respectively. The invariance properties of clusters under for I = 1, 3/2 and 5/2 are derived for both | IMα> and | kqv≫ spaces. A general {[Xtilde] i } form over the total Liouville space is given for arbitrary Ii . In the context of the multiquantum N.M.R. of spin clusters, these properties allow one to construct a density operator strictly under the dual groups; such tensors provide a valid -partitioned quantum-Liouville description, of both evolution and relaxation processes, which is applicable to non-magnetically equivalent spin systems, such as [AX]4 under . For bicluster systems specific aspects of recoupling theory, implicit in the evaluation of reduced matrix elements (RME), are examined; explicit basis and RME forms under are considered. Combinatorics are shown to play a large role in characterizing the various spaces, |IMα: Sn >, | kqv: Sn ≫ and , by allowing direct evaluations of the pertinent invariances and components under .
Molecular Physics•Apr 20, 1989•26 citations