For compiling recent CHARMM releases (c34 and later) on Mac systems running OS X 10.6 (Xcode 3.2.2, gfortran 4.5 from http://hpc.sourceforge.net), I found the following two changes were needed for e.g.

./install.com osx xlarge x86_64 gfortran

(1) install.com, in "case osx:" section, for trajectory compatibility change

else
echo "GNU" >! $chmbuild/pref$$.dat
echo "GFORTRAN" >>! $chmbuild/pref$$.dat
endif

to add the I4BINARY pref.dat keyword

else
echo "GNU" >! $chmbuild/pref$$.dat
echo "GFORTRAN" >>! $chmbuild/pref$$.dat
if( $longint == 1 ) then
echo "I4BINARY" >>! $chmbuild/pref$$.dat
endif
endif

and (2) in build/UNX/Makefile_osx, ca. line 64, change

else
FFLAGS := $(FFLAGS) -march=pentium3 -mtune=pentium3
endif
FC = $(FCOMPILER) -DGNU $(FFLAGS)
LD = $(FCOMPILER) -O2 $(FFLAGS)

to make 8-byte integers the default for 64-bit via

else
FFLAGS := $(FFLAGS)
endif
ifdef X86_64
FC = $(FCOMPILER) -DGNU $(FFLAGS) -fdefault-integer-8
LD = $(FCOMPILER) -O2 $(FFLAGS) -fdefault-integer-8
else
FC = $(FCOMPILER) -DGNU $(FFLAGS)
LD = $(FCOMPILER) -O2 $(FFLAGS)
endif



Edited by rmv (05/26/10 01:59 PM)
_________________________
Rick Venable
computational chemist