Program title: HFFERII
Catalogue identifier: AECC_v2_1
Program summary URL: 聽
Program obtainable from: CPC Program Library, Queen鈥檚 University, Belfast, N. Ireland
Licensing provisions: Standard CPC licence,
No. of lines in distributed program, including test data, etc.: 2521
No. of bytes in distributed program, including test data, etc.: 310856
Distribution format: tar.gz
Programming language: Fortran 95.
Computer: Cluster of 1-13 HP Compaq dc5750.
Operating system: Linux.
Has the code been vectorized or parallelized?: Yes, with MPI directives.
RAM: 1 GByte per node
Classification: 2.1.
External routines: MPI/GFortran, LAPACK, BLAS, FMlib (included in the package).
Catalogue identifier of previous version: AECC_v2_0
Journal reference of previous version: Comput. Phys. Comm. 183(2012)1502
Does the new version supercede the previous version?: Yes
Nature of problem:
Quantitative modelings of features observed in the X-ray spectra of isolated magnetic neutron stars are hampered by the lack of sufficiently large and accurate databases for atoms and ions up to the last fusion product, iron, at strong magnetic field strengths. Our code is intended to provide a powerful tool for calculating energies and oscillator strengths of medium- atoms and ions at neutron star magnetic field strengths with sufficient accuracy in a routine way to create such databases.
Solution method:
The Slater determinants of the atomic wave functions are constructed from single-particle orbitals which are products of a wave function in the direction (the direction of the magnetic field) and an expansion of the wave function perpendicular to the direction of the magnetic field in terms of Landau states, . are expansion coefficients, and the expansion is cut off at some maximum Landau level quantum number . In the previous version of the code only the lowest Landau level was included (), in the new version can take values of up to 7. As in the previous version of the code, the longitudinal wave functions are expanded in terms of sixth-order -splines on finite elements on the axis, with a combination of equidistant and quadratically widening element borders. Both the -spline expansion coefficients and the Landau weights of all orbitals have to be determined in a doubly self-consistent way. For a given set of Landau weights , the system of linear equations for the -spline expansion coefficients, which is equivalent to the Hartree-Fock equations for the longitudinal wave functions, is solved numerically. In the second step, for frozen -spline coefficients new Landau weights are determined by minimizing the total energy with respect to the Landau expansion coefficients. Both steps require solving non-linear eigenvalue problems of Roothaan type. The procedure is repeated until the convergence of both the -spline coefficients and the Landau weights are achieved.
Reasons for new version:
The description of states with partial spin polarization, which are relevant in the regime of low to intermediate magnetic field strengths , was not included in the version published previously but is vital to gain access to these regimes of the magnetic field strength.
Summary of revisions:
In this new version, we included the electron spin orientation, enhanced the convergence behavior, reduced the output, sped up the program and built a new result file type, which offers a greater flexibility and reduces file sizes.
Restrictions:
Intense magnetic field strengths are required, since the expansion of the transverse single-particle wave functions using 8 Landau levels will no longer produce accurate results if the scaled magnetic field strength parameter becomes much smaller than unity.
Unusual features:
A huge program speed-up is achieved by making use of pre-calculated binary files. These can be calculated with additional programs provided with this package.
Running time:
1-30 min