Elsevier Science Home
Computer Physics Communications Program Library
Full text online from Science Direct
Programs in Physics & Physical Chemistry
CPC Home

[Licence| Download | New Version Template] aafl_v1_0.gz(15 Kbytes)
Manuscript Title: IPPP: a program for the RPA calculation of transmission mechanisms of spin-spin coupling constants.
Authors: A.R. Engelmann, M.A. Natiello, G.E. Scuseria, R.H. Contreras
Program title: IPPP
Catalogue identifier: AAFL_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 39(1986)409
Programming language: Fortran.
Computer: IBM 370/158.
Operating system: VM/CMS.
RAM: 1528K words
Word size: 32
Keywords: Quantum chemistry, Molecular physics, Structure, Nmr transmission mechanisms - RPA - INDO - IPPP.
Classification: 16.1.

Nature of problem:
The IPPP program calculates NMR spin-spin coupling constants in molecular systems, based on a standard INDO computation, within the RPA (or CHF) approximation solved by the polarization propagator technique. The transmission mechanisms are analyzed by the inner projection of the propagator matrix.

1. The ground state of the molecular system under study must be a closed-shell restricted Hartree Fock state.
2. The number of orbitals and excitations are limited to: 53 atomic orbitals, 35 doubly occupied (or virtual) molecular orbitals and 315 proper excitations (occupied orbitals * virtual orbitals).

Running time:
The ethylene test run takes 3 sec. for the INDO segment and 19 sec. for the IPPP segment on an IBM 370/158.