Configuration space Faddeev calculations. V. Variational bounds

Three three-nucleon model problems are proposed as test cases for numerical computation: the ground and excited states of a spin-isospin independent Yukawa potential (Delves potential) and the ground state of a spin-isospin independent potential composed of one attractive and one repulsive Yukawa function (Malfliet-Tjon V). Eigenvalues and eigenfunctions are calculated using a configuration space Faddeev approach, and variational upper and lower bounds are evaluated using these wave functions. Each calculation is performed both as a projected $s$-wave potential problem, and as a true local potential problem in which nucleon-nucleon partial waves through $l=6\mathrm{}$ are kept. For each case the eigenvalue appears to be converged to within 1 keV and it agrees well with the upper bound. A brief review of bounding techniques is presented.