An atomic Dirac-Fock-Roothaan program. O. Matsuoka, Y. Watanabe.

PROGRAM SUMMARY
Title of program: DFRATOM
Catalogue identifier: ADOK
Ref. in CPC: 139(2001)218
Distribution format: gzip file
Operating system: Solaris 2.5.1
High speed store required: 26MK words
Number of bits in a word: 32
Peripherals Required: disc
Number of lines in distributed program, including test data, etc: 3239
Keywords: Atomic physics, Dirac-Fock-Roothaan method, Gaussian-type function, Average energy of configurations, Point-charge nucleus, Uniformly charged sphere nucleus, Gaussian-charge distribution nucleus, Relativistic effect, Structure.
Programming language used: Fortran
Computer: FUJITSU S-7/300U .

Nature of problem:
The Dirac-Fock-Roothaan equations for 4-component atomic orbitals are solved using Gaussian-type basis functions. The program provides atomic total energies, orbital energies, and radial expectation values as well as atomic self-consistent-field orbitals.

Method of solution:
The self-consistent-field equations for an atom in the generalized average energy of configurations [1] are set up and solved following one of author's method [2]. The Gaussian-type basis functions are employed to express the 4-component atomic orbitals. The strict kinetic balance scheme [3] is adopted between the large and the small component primitive Gaussians.

Restrictions:
The present version of the program can handle up to seven symmetry species and one open-shell of the highest orbital energy for each symmetry species.

Typical running time:
Three test examples took 0.7 s (carbon), 57 s (iodine), and 106 s (uranium), respectively.

References:

 [1] J.P. Desclaux, C.M. Moser, V. Verhaegen, J. Phys. B 4 (1971) 296.   
 [2] O. Matsuoka, J. Phys. Soc. Jpn. 51 (1982) 2263.                     
 [3] R.E. Stanton, S. Havriliak, J. Chem. Phys. 81 (1984) 1910.