four_couple# four_couple(js, angles)[source]# The R-factor \[R^{(0)}_{0}(\boldsymbol{\epsilon}; \mathbf{J}) = \sum_{k=0}^{2} T^{(0)}_{0}(\boldsymbol{\epsilon}; k, k) G(\mathbf{J}; k)\] j values in js correspond to bras associated with dipole operators
