PairDiag: an exact diagonalization program for solving general pairing Hamiltonians

Understand

We present a program for solving exactly the general pairing Hamiltonian based on diagonalization.

• The program generates the seniority-zero shell-model-like basis vectors via the `01' inversion algorithm.
• The Hamiltonian matrix is constructed in that seniority-zero space.
• The program evaluates all non-zero elements of the Hamiltonian matrix "on the fly" using the scattering operator and the search algorithm that act on the generated basis.