  A well known recurrence relation for the 6j-symbol of the quantum group
su_q(2) is realized as a tridiagonal, symmetric eigenvalue problem. This
formulation can be used to implement an efficient numerical evaluation
algorithm, taking advantage of existing specialized numerical packages. For
convenience, all formulas relevant for such an implementation are collected in
the appendix. This realization is a byproduct of an alternative proof of the
recurrence relation, which generalizes a classical (q=1) result of Schulten and
Gordon and uses the diagrammatic spin network formalism of Temperley-Lieb
recoupling theory to simplify intermediate calculations.
