Theoretica chimica acta

, Volume 46, Issue 2, pp 129–141 | Cite as

The computation of the representation matrices of the generators of the unitary group

  • Michael J. Downward
  • Michael A. Robb
Original Investigations


A method is presented for the efficient computation of the representation matrices of the unitary group, U(n) in the Gelfand—Tsetlin basis (corresponding to the usual spin-symmetry adapted basis for an N electron CI). The present scheme is conceptually and computationally attractive in that it is formulated directly in terms of Weyl tableaux and also that it permits simultaneous basis vector generation and matrix element evaluation. In addition the basis vectors are ordered so that subsequent restriction to the three dimensional rotation group is facilitated. An illustrative example is also presented.

Key words

Representation matrices of the unitary group Configuration interaction symmetric group 


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Copyright information

© Springer-Verlag 1977

Authors and Affiliations

  • Michael J. Downward
    • 1
  • Michael A. Robb
    • 1
  1. 1.Department of ChemistryQueen Elizabeth CollegeLondonUK

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