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Manuscript Title: ABC: a quantum reactive scattering program.
Authors: D. Skouteris, J.F. Castillo, D.E. Manolopoulos
Program title: ABC
Catalogue identifier: ADMX_v1_0
Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 133(2000)128
Programming language: Fortran.
Computer: SGI Origin 200, Compaq DS20.
Operating system: IRIX, Digital UNIX.
RAM: 128M words
Word size: 32
Keywords: Molecular physics, Quantum reactive scattering, Hyperspherical coordinates, Chemical reaction dynamics.
Classification: 16.8.

Nature of problem:
The calculation of accurate quantum mechanical reaction probabilities and state-to-state integral and differential cross sections for atom-diatom chemical reactions.

Solution method:
The ABC program uses a coupled-channel hyperspherical coordinate method to solve the Schrodinger equation for the motion of the three nuclei (A, B, and C) on a single Born-Oppenheimer potential energy surface. The coupled-channel method used involves a simultaneous expansion of the wavefunction in the Delves hyperspherical coordinates of all three chemical arrangements (A+BC, B+CA, C+AB). The quantum reactive scattering boundary conditions are applied exactly, without the use of an imaginary absorbing potential, and the coupling between orbital and rotational angular momenta is also implemented correctly for each value of the total angular momentum quantum number.
The program uses the BLAS routines dgemm, dgemv, and dsyr and the LAPACK routines dgetrf, dgetrs, dsytrf, dsytri, dsyev and dstev.

The present version of the program is restricted to the H + H2, F + H2 and Cl + H2 reactions and their deuterium-substituted isotopomers. Potential energy surfaces for other reactions may be included in future releases.

Running time:
Highly dependent on the input parameters. For the F + HD test calculation given, approximately 30 minutes on a Compaq DS20 workstation.