[gmx-users] gromacs on MacOSX. It works great!

[nicolis at guideo.fr]

Well I am not sure that somebody else wants to use gromacs on 
macintosh under system OSX, but just in case you are interested it works 
just fine.

Of course it doesn't work under the aqua environment but under 
X-windows. You have to install XDarwin first. I assume also that you have 
installed fftw and optionnally lesstiff before.
There are only three points to modify from the standard installation 
procedure:

*	First, configure looks for malloc.h in the /usr/include directory, but under 
MacOSX it is in /usr/include/objc/
The simplest way I found is to establish a soft link:
sudo ln -s /usr/include/objc/malloc.h /usr/include/malloc.h 
After that, you can proceed typing ./configure 

*	The second problem arises at the end of the configuration. configure is 
unable to create the makefiles complaining about a series of sed errors 
like these ones:
sed: 48: /tmp/cs6564-15022/subs-1.sed: unescaped newline inside 
substitute pattern
sed: 3: /tmp/cs6564-15022/subs-2.sed: command i expects \ followed by 
text 
These errors come from some commands in the config files wrapped on 
two lines. For a reason I don't understand (could be a unix/mac end of line 
issue?), sed wants some commands on the same line but the configure 
script splits them on two lines. To correct the problem open (with emacs 
or any other editor) the config.status file and look near the end of the file 
for the 7 lines beginning:
s, at ACLOCAL@,${SHELL} 
s, at AUTOCONF@,${SHELL} 
s, at AUTOMAKE@,${SHELL} 
s, at AUTOHEADER@,${SHELL} 
s, at MAKEINFO@,${SHELL} 
s, at AMTAR@,${SHELL} 
s, at install_sh@, 
They are followed by a path on the same line and a second path on the 
next line. Just delete the end of line to join the two lines for each of the 
seven commands (taking care to leave a space between the two paths).
After saving the file, type 
./config.status 
and the makefiles will be generated.
You can now type 
make 
in order to build the package and 
sudo make install 
to install it.

*	The third issue comes upon grompp execution.
grompp uses the c-preprocessor to resolve includes etc. If you want to 
use this functionality you have to know that grompp looks for /lib/cpp but 
on MacOSX it is under /usr/libexec/gcc/darwin/ppc/2.95.2/cpp. Again, the 
simplest way I found is a soft link:
sudo ln -s /usr/libexec/gcc/darwin/ppc/2.95.2/cpp /lib/cpp 
(of course you can also indicate in the grompp inmput file where cpp is)

That's all. I hope it works for you as it worked for me. Any comments (and 
error corrections) are welcomed.

Yiannis

P.S. I made the same info available on the page 
<http://ioannis.nicolis.online.fr/macosx/gromacs.html>
Please let me know if there is a problem with that.