Programs in Physics & Physical Chemistry
|[Licence| Download | New Version Template] aehs_v1_0.tar.gz(153 Kbytes)|
|Manuscript Title: Fast computation of close-coupling exchange integrals using polynomials in a tree representation|
|Authors: Markus Wallerberger, Katharina Igenbergs, Josef Schweinzer, Friedrich Aumayr|
|Program title: TXINT|
|Catalogue identifier: AEHS_v1_0|
Distribution format: tar.gz
|Journal reference: Comput. Phys. Commun. 182(2011)775|
|Programming language: Fortran 95.|
|Computer: All with a Fortran 95 compiler.|
|Operating system: All with a Fortran 95 compiler.|
|RAM: Depends heavily on input, usually less than 100 MiB|
|Keywords: Exchange integrals, Symbolic manipulations, Polynomials.|
Nature of problem:
Analytical calculation of one- and two-center exchange matrix elements for the close coupling method in the impact parameter model.
Similar to the code of Hansen and Dubois , we use the Fourier transform method suggested by Shakeshaft  to compute the integrals. However, we heavily speed up the calculation using a library for symbolic manipulation of polynomaials.
We restrict ourselves to a defined collision system in the impact parameter model.
A library for symbolic manipulation of polynomials, where polynomials are stored in a space-saving left-child right-sibling binary tree. This provides stable numerical evaluation and fast mutation while maintaining full compatibility with the original code.
This program makes heavy use of the new features provided by the Fortran 90 standard, most prominently pointers, derived types and allocatable structures and a small portion of Fortran 95. Only newer compilers support these features.
Following compilers support all features needed by the program.
Heavily dependent on input, usually less than one CPU second.
|||Hansen, J.-P. and Dubois, A., Comput. Phys. Commun. 67 (1992) 456 .|
|||Shakeshaft, R., J. Phys. B: At. Mol. Opt. Phys. 8 (1975) L134.|
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