[gmx-users] QM/MM

[Ramon Crehuet]

Dear all,
This is a follow-up of a previous question and I'll try to be as precise
as possible. I'd like to use QM/MM interface with MOPAC and Gaussian 03.
Here are my questions.
1. In Grubmueller's page the link to MOPAC7 is broken, but one can get
mopac7.tar.gz. This file seems to be the modified version, because it
already contains gmxmop.f. And it seems to be the SGI version (but they
differ in one line). So should I replace the gmxmop.f in mopac7.tar.gz
with the linux version?
2. I'd like to compile with ifort but Gerrit told me they got unreliable
results. In which sense are they unreliable? He recommended a f2c/gcc
approach with 32-bit architecture, but mine is 64-bit. Can I use f77?
When should I expect problems, when compiling gromacs or when executing
(harder to trace!)?
3. Apart from setting --with-qmmm-gaussian when compiling gromacs, how
should I proceed to compile with gaussian? Do I need to recompile
gaussian? Tell gromacs where the gaussian sources/objects are? Gaussian
is usually compiled with Portland compilers... are they compatible with
gromacs?

Please, comment if you have some experience with *any* of these points.
I'll gladly share mine when I get something woriking.

Cheers,
Ramon