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Manuscript Title: Orthogonal generalized Jacobi coordinates for N-body systems.
Authors: K. Davie, R. Wallace
Program title: GJVGEN
Catalogue identifier: ABJJ_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 55(1989)463
Programming language: Fortran.
Computer: IBM PC/AT.
Operating system: DOS 3.0 OR LATER.
Keywords: Molecular physics, Structure, Orthonormalization, Gram-schmidt, Equivalent symmetric, Irreducible symmetric.
Classification: 16.1.

Nature of problem:
Removal of the centre of mass motion for any N-body system leaves the internal motion described by a series of vectors which are nonorthogonal in the configuration space describing relative motion. It is advantageous to define new vectors (GJV) which are orthogonal. Such orthogonalization can be achieved in a wide variety of ways. In quantum mechanical applications, it is especially valuable to define GJV reflecting system symmetry. Such coordinates lead to simplifications of the resultant Hamiltonian for relative motion.

Solution method:
Algorithms have been implemented which systematically orthogonalize coordinates either sequentially for partitioned parts of a molecule or simultaneously for the entire molecule. Orthonormalization schemes such as Gram-Schmidt (GS), equivalent symmetric (ES), or irreducible symmetric (IS) may be independently chosen for each partitioned fragment.

The size of the n * n matrices used in the program are such that transformation matrices for 2 to 14 atom molecules can be generated.

Running time:
For N=5 (CH 2 * Cl 2): Totally Symmetric (Norm independent) - 25 sec. Totally Symmetric (Norm dependent) - 12 sec. Gram Schmidt - 1 sec. Irreducible Symmetric - < 1 sec.