PROGRAM SUMMARY
Title of program:
CONTWVSA version 1.0
Catalogue identifier:
ADPC
Ref. in CPC:
141(2001)205
Distribution format: tar gzip file
Operating system: Digital UNIX V4.0D, LINUX RedHat 6.2
High speed store required:
19MK words
Number of bits in a word:
8
Number of lines in distributed program, including test data, etc:
16698
Keywords:
Continuum wavefunctions, Relativistic effects, Dirac-Fock,
Atomic physics, Structure.
Programming language used: Fortran
Computer:
Digital Personal Work- ,
station 500, Intel i386 .
Other versions of this program:
Cat. Id. Title Ref. in CPC ACNK CONTWVG 76(1993)250
Nature of physical problem:
The relativistic Dirac-Fock equations are set up and solved numerically
for continuum wavefunctions.
Method of solution:
Relativistic atomic wavefunctions are calculated using a central
differences method with deferred corrections. The grid spacing at large
radial distances (the linear region of the two-piece grid) is
automatically determined to provide at least 10 grid points per half
cycle of the wavefunction. Lagrange multipliers are automatically
calculated without additional input. Extra angular coefficients are
read from a separate input file.
Reasons for the new version:
The new version is required for obtaining relativistic continuum
orbitals for a wider range of configurations.
Summary of revisions:
This new version is independent of the GRASP package [1]. Additional
angular structure needed for some open shell systems is now read from an
extra input file. The convergence behavior is improved by choosing a
hydrogenic continuum wavefunction as starting point for the
self-consistent field process and the possibility of using a previously
calculated continuum orbital as starting point is included.
Restrictions:
Continuum orbitals for atoms ranging from hydrogen to mercury have been
calculated, with up to six Lagrange multipliers and energies from zero
to 100 atomic units. Cases outside of these limits will likely also
succeed.
Typical running time:
The typical running time is 10 seconds to 1 minute on a Digital-Personal
Workstation model 500.
Unusual features:
The program will calculate a virtual state V**(B-1) continuum orbital
for a given K quantum number and dump that orbital to a file. The
program uses a relativistic WKB approximation for normalization of the
continuum orbital in the presence of a non-neural core and it uses a
curve-fitting procedure for normalization in the case of a neutral core.
The spacing of the radial grid at large radial distances, where the
two-piece grid is linear, is automatically calculated to provide at
least 10 grid points per half cycle. Additional angular structure
needed for some open shell systems is read from an extra input file to
enhance the set of treatable systems. For better convergence the
possibility of using a previously calculated continuum orbital as
starting point for the self-consistent field process has been included.
References:
[1] K.G. Dyall, I.P. Grant, C.T. Johnson, F.A. Parpia, E.P. Plummer,
Comput. Phys. Commun. 55 (1989) 425.