ATSP is a set of legacy Fortran programs developed by Charlotte Froese Fischer and coworkers. The ATSP package may be used to compute atomic energy levels, wavefunctions, and other properties of atomic states in the multi-configuration Hartree-Fock approximation. Numerous papers in computational atomic structure reference the ATSP package.

This page describes one version of ATSP maintained by ccreweb.org. Other legacy, modernized, and extended versions of ATSP also exist. See links at left for versions provided by the CompAS research group.

The ccreweb.org-maintained ATSP package is based on the source code from Prof. Charlotte Froese Fischer's research group, released on December 20, 1996. The code has subsequently been modified with the primary goal of ensuring that it builds under recent versions of the GNU Fortran compiler and executes correctly sample test cases.

The primary documentation for the ATSP programs is the book, Computational Atomic Structure: An MCHF Approach, by C. Froese Fischer, T. Brage, and P. Jönsson, Institute of Physics (Bristol, 1997). Details of the program are also documented in a later paper from 2000 by Fischer: The MCHF atomic-structure package. The paper is accompanied by a version of the ATSP package from 1999. This "atsp-book" version is licensed by the authors for non-profit and academic use only. Later versions of the authors' code are licensed under the more permissive MIT License.

To the best of our knowledge, earlier versions such as the 20 Dec 1996 version, on which the ccreweb.org version is based, were not accompanied by a software license. We hope that the software provided here will be useful for education and research purposes e.g., verifying published results. Please note that we make no guarantees of the correctness of our changes or the resulting accuracy of the computations: use this code at your own discretion.

      The MCHF Atomic Structure Package
      ==================================

        Charlotte Froese Fischer

        and collaborators:

         Alan Hibbert and Ronnie Glass
         Michel R. Godefroid
         Bin Liu
         Tomas Brage
         Gregory Miecznik
         Nathalie Vaeck
         Per J\"onsson
         Claes Goran Wahlstrom
         Jinhua Xi
         Gediminas Gaigalas

         December 20, 1996
         -----------------

Revisions to the ccreweb.org-maintained code were made by

• Krishna Myneni, ccreweb.org
• Ondrej Certik, LANL