THIS INFORMATION IS OBSOLETE AND IS PROVIDED ONLY FOR ITS HISTORICAL VALUE

3JHH (QCPE 461) is a program designed to calculate vicinal coupling constants from MM2 optimized geometries. It is based upon a Karplus-type equation as suggested by Haasnoot, De Leuwe and Altona. Recently, it was discovered that the original program incorrectly calculated local C2v symmetry to pairs of methylene protons under certain circumstances.

The program has now been modified to eliminate the problems of the original. 3JHHPC, in its current form is distributed for use under MS-DOS/PC-DOS (but is also suitable for use in UNIX, VMS and TOPS-10 operating environments). The modifications include (1) correction of subroutine HCOREC, so that methylene proton coordinates are correctly calculated with local C2v symmetry, (2) inclusion of an interactive question-and- answer session to specify program options, (3) increase of the number of bonds (from 5 to 10) for which the vicinal couplings can be calculated, so that all the couplings of medium-size rings(mostespecially substituted cyclohexanes) can be calculated during one program session, and (4) printing of the calculated 1H vicinal couplings at the user's terminal, so that waiting for the results from a line printer (especially on multiuser systems) is eliminated. Included is a subroutine, JHH.FOR, that can be placed at the end of MM2 to generate the coordinate files suitable for input into 3JHHPC. The subroutine is best called from subroutines CE1/CE3 directly after the energy calculations.

All I/O statements have been modified so that all channel dependencies are eliminated.

FORTRAN 77 (Microsoft FORTRAN) Lines of Code: 1700