We present a program for solving exactly the general pairing Hamiltonian based on diagonalization. The generates seniority-zero shell-model-like basis vectors via ‘01’ inversion algorithm. matrix is constructed in this space. evaluates all non-zero elements of “on fly” using scattering operator and search diagonalized by iterative Lanczos OpenMP parallel thus developed, PairDiag, can efficientl...

The exact numerical diagonalization of the Hamiltonian of a 2D circular quantum dot is performed for 2, 3, and 4 electrons.The results are compared with those of the perturbation theory.Our numerical results agree reasonably well for small values of the dimensionles coupling constant λ = a a B where a is the dot radius and a B is the effective Bohr radius.Exact diagonalization results are compa...