Single particle calculations for a Woods-Saxon potential with triaxial deformations, and large Cartesian oscillator basis
مقال من تأليف: Mohammed-Azizi, B. ; Medjadi, D. E. ;
ملخص: We present a computer program which solves the Schrodinger equation of the stationary states for an average nuclear potential of Woods-Saxon type. In this work, we take specifically into account triaxial (i.e. ellipsoidal) nuclear surfaces. The deformation is specified by the usual Bohr parameters. The calculations are carried out in two stages. In the first, one calculates the representative matrix of the Hamiltonian in the Cartesian oscillator basis. In the second stage one diagonalizes this matrix with the help of subroutines of the Eispack library. If it is wished, one can calculate all eigenvalues, or only the part of the eigenvalues that are contained in a fixed interval defined in advance. In this latter case the eigenvectors are given conjointly. The program is very rapid, and the run-time is mainly used for the diagonalization. Thus, it is possible to use a significant number of the basis states in order to insure a best convergence of the results.Program summaryProgram obtainable from:CPC Program Library, Queen's University of Belfast, N. IrelandTitle of program:TriaxialCatalogue number:ADSKProgram summary URL:http://cpc.cs.qub.ac.uk/summaries/ADSKLicensing provisions:NoneComputer:PC. AMD Athlon 1000 MHzHard disk:40 GoRam:256 MoSwap file:4 GoOperating system:WINDOWS XPSoftware used:Microsoft Visual Fortran 5.0A (with full optimizations in the settings project options)Programming language:Fortran 77/90 (double precision)Number of bits in a word:32Number of lines:7662No. of bytes in distributed program, including test data, etc.:174 601Distribution format:tar gzip fileNature of the problem: The single particle energies and the single particle wave functions are calculated from one-body Hamiltonian including a central field of Woods-Saxon type, a spin-orbit interaction, and the Coulomb potential for the protons. We consider only ellipsoidal (triaxial) shapes. The deformation of the nuclear shape is fixed by the usual Bohr parameters ([beta],[gamma]).Method of solution: The representative matrix of the Hamiltonian is built by means of the Cartesian basis of the anisotropic harmonic oscillator, and then diagonalized by a set of subroutines of the Eispack library. Two quadrature methods of Gauss are employed to calculate respectively the integrals of the matrix elements of the Hamiltonian, and the integral defining the Coulomb potential.Restrictions: There are two restrictions for the code: The number of the major shells of the basis does not have to exceed Nmax=26. For the largest values of Nmax (~23-26), the diagonalization takes the major part of the running time, but the global run-time remains reasonable.Typical running time: (With full optimization in the project settings of the Microsoft Visual Fortran 5.0A on Windows XP.) With Nmax=23, for the neutrons case, and for both parities, if we need all eigenenergies and all eigenfunctions of the bound states, the running time is about 80 sec on the AMD Athlon computer at 1 GHz. In this case, the calculation of the matrix elements takes only about 20 sec. If all unbound states are required, the runtime becomes larger.
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إنجليزية