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Manuscript Title: A general multi-configuration Hartree-Fock program.
Authors: C.F. Fischer
Program title: MCHF77
Catalogue identifier: ACYA_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 14(1978)145
Programming language: Fortran.
Computer: IBM S370/168.
Operating system: OS/MVT RELEASE 21-8.
RAM: 69K words
Word size: 32
Keywords: Atomic physics, Structure, Numerical hartree-fock, Configuration Interaction, Bound state, Schrodinger equation, Self-consistent field, Energy level.
Classification: 2.1.

Other versions:
Cat Id Title Reference
ACRF_v1_0 MCHF72 CPC 4(1972)107
AATK_v1_0 HF86 CPC 43(1987)355

Nature of problem:
Numerical non-relativistic Hartree-Fock results are determined within the multi-configuration approximation for atoms in a bound state.

Solution method:
The self-consistent field method of solution is employed. In a multi- configuration calculation the mixing coefficients are adjusted periodically as part of the SCF iteration. Two methods of solution of of the differential equations are used, each improving only a single function at a time, and rotations are introduced explicitly to find on energy stationary with respect to a rotation of the orbital basis. Otherwise the procedures are essentially the same as those in MCHF72.

The possible configurations are restricted to those for which the interactions can be expressed as either F**k, G**k, R**k or Inl,n'l integrals. Configurations differing by one electron may be included provided that the resulting MCHF problem has a unique solution. Since bound states in the continuum interact most strongly with continuum states, a multi-configuration calculation for such states cannot be performed with this program.

Unusual features:
The orgranization of the program is such that the "frozen core" approximation may be used and orbitals with zero occupation number are allowed. Orbitals in different configurations may be allowed to differ so long as not more than one overlap integral enters into the expresson for the interaction and the expressions for off-diagonal energy parameters remain relatively simple. A fixed zero-order approximation may be employed resulting in a considerable saving in computation time in some cases.