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[Licence| Download | New Version Template] acqi_v1_0.gz(11 Kbytes)
Manuscript Title: Hartree Fock Slater self consistent field calculations.
Authors: J.P. Desclaux
Program title: H.F.S. SELF CONSISTENT FIELD
Catalogue identifier: ACQI_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 1(1970)216
Programming language: Fortran.
Computer: IBM 360/50.
Operating system: O S MFT 2.
RAM: 22K words
Word size: 32
Keywords: Atomic physics, Structure, Hartree-fock equations, Free electron exchange Potential, Eigenfunctions, Eigenvalues, Numerov method, Pratt improvement scheme.
Classification: 2.1.

Revision history:
Type Tit le Reference
adaptation 0001 ADAPT HFS FOR MSXALPHA See below

Nature of problem:
With present programs the Hartree-Fock (H.F.) equations can be treated for nearly all configurations. It has been shown, however, that accurate electron binding energies can be obtained without use of the comparatively complicated H.F. scheme. Since the main difficulty posed by the H.F. equations is the treatment of the non local exchange potential it would be desirable to find a good local approximation to the H.F. potential. The approximation suggested by Slater is used in this program as it has been in many atomic or energy band calculations.

Solution method:
The H.F. equations are solved by the "IN-OUT" method described by Hartree. The numerical procedure is that of Numerov with the "tail procedure" introduced by Froese. The improvement scheme of Pratt is used to accelerate the convergence.

Restrictions:
In the present work single electronic configurations having one or more open shells are treated on the same basis as closed shells configurations. The distinctive features introduced by the presence of unmatched spins are not considered. The electronic configuration is specified by the orbital occupation numbers only. The program is restricted to free atoms or positive ions and the maximum number of one electron orbitals is 20.

Running time:
The test case (neutral mercury atom) requires 110 seconds to compile and 151 seconds to run on the IBM 360/50 computer. The starting potential being the Thomas Fermi potential for the free atom, an analytical approximation of which is included in the program.

ADAPTATION SUMMARY
Manuscript Title: An adaptation of ACQI to calculate the data for MSXALPHA program.
Authors: M. Klobukowski
Program title: 0001 ADAPT HFS FOR MSXALPHA
Catalogue identifier: ACQI_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 25(1982)29
Programming language: Fortran.
Computer: AMDAHL 470/V7.
Operating system: MTS.
RAM: 76K words
Word size: 8
Peripherals: disc.
Classification: 2.1.

Nature of problem:
The adaptation allows one to prepare the numerical atomic orbitals data to be used by the new version of the SCF Xalpha scattered wave program MSXALPHA/II. The output file produced by the present adaptation conforms to the data requirement of that program.

Solution method:
The Hartree-Fock-Slater calculations are carried out for all the unique atoms of the molecule to be treated later by the MSXALPHA/II program. The atomic results are next restored from work files and rearranged into a form suitable for input to the MSXALPHA/II program.

Restrictions:
Due to dimensions of some arrays in subroutine MSINPT a maximum of 10 unique atoms may be treated. However, this restriction may be easily removed by increasing the array dimensions. Other restrictions (maximum number of orbitals per atom, maximum number of integration points) are the same as those in the original program ACQI.

Running time:
The CPU time required to compile the modified program was 6.3 s(FORTRAN H compiler). It took 2.7 s of CPU time to run the first test run, and 3.3 s to run the second test run.