A fast iterative route to the optimal angle of rotation in the complex coordinate rotation method: some model applications

The Hellmann-Feynman theorem is invoked for the complex-rotated Hamiltonian leading to an algebraic θ-equation which can be solved easily yielding the optimum rotation angle. The stabilized pole positions and their widths are then obtained cost-effectively without having to construct familiar θ-trajectories. Model applications indicate the efficacy of the procedure suggested.