Calculation of the matrix elements of the Coulomb interaction involving relativistic hydrogenic wave functions. L. Lugosi, L. Sarkadi.

PROGRAM SUMMARY
Title of program: MTRDCOUL
Catalogue identifier: ADOX
Ref. in CPC: 141(2001)73
Distribution format: gzip file
Operating system: MS-DOS
High speed store required: 200K words
Number of bits in a word: 8
Number of lines in distributed program, including test data, etc: 2102
Keywords: Coulomb interaction, Matrix elements, Ionization, Relativistic hydrogenic wave functions, Dirac-Coulomb functions, Multipole series expansion, Atomic physics.
Programming language used: Fortran
Computer: IBM compatible PC .

Nature of physical problem:
The theoretical description of the excitation and ionization of atoms by charged particle impact often requires the knowledge of the matrix elements of the Coulomb interaction. The program MTRDCOUL calculates the matrix elements between bound and free states represented by relativistic hydrogenic wave functions.

Method of solution:
The multipole series expansion of the Coulomb potential is used to solve the problem. The program uses the subprograms F3Y [1] (catalogue identifier: AAQQ) and DCOUL [2] (catalogue identifier: ADBP). The subprograms are included in the distributed program.

Restrictions:
The matrix elements are calculated with the following restrictions. The initial bound states are limited to 1s1/2, 2s1/2, 2p1/2, 2p3/2, 3s1/2, 3p1/2, 3p3/2, 3d3/2, 3d5/2. The quantum number l in the final state has a maximum value of 10.

Typical running time:
The test run requires about 170 s.

References:

 [1] A. Liberato de Brito, Comput. Phys. Commun. 25 (1982) 81.           
 [2] F. Salvat, J.M. Fernandez-Varea, W. Williamson Jr., Comput. Phys.   
     Commun. 90 (1995) 151.