Application of the gradient method to Hartree-Fock-Bogoliubov theory

A computer code is presented for solving the equations of the Hartree-Fock-Bogoliubov (HFB) theory by the gradient method, motivated by the need for efficient and robust codes to calculate the configurations required by extensions of the HFB theory, such as the generator coordinate method. The code is organized with a separation between the parts that are specific to the details of the Hamiltonian and the parts that are generic to the gradient method. This permits total flexibility in choosing the symmetries to be imposed on the HFB solutions. The code solves for both even and odd particle-number ground states, with the choice determined by the input data stream. Application is made to the nuclei in the sd shell using the universal sd-shell interaction B (USDB) shell-model HamiltonianThis work (G.F.B.) was supported in part by the US Department of Energy under Grant No. DE-FG02-00ER41132, and by the National Science Foundation under Grant No. PHY-0835543. The work of L.M.R. was supported by MICINN (Spain) under Grants No. FPA2009-08958 and No. FIS2009-07277, as well as by Consolider-Ingenio 2010 Programs CPAN No. CSD2007-00042 and MULTIDARK No. CSD2009-0006