[sci.chem] fix to potential problem in Mopac 6.0

bbesler@vela.acs.oakland.edu (Brent H. Besler) (02/18/91)

If you are having problems compiling Mopac 6.0 on some Unix systems,
particularly in compiling the subroutine deri2.f try the following fix:

There is a line in the SIZES file(unix version or dimsizes.dat in the
Vax version) about 75% of the way down where NMECI=1 and NPULAY=1.
There is a line above it where NMECI=10.  By default the CI in Mopac is
disabled in the Unix version to reduce the memory required.  This works
on most systems, but on some the compiler balks.  Try uncommenting the
line with NMECI=10 and commenting out the one with NMECI=1.