
                    ######################################
                    Tinker Notes for GNU gfortran on macOS
                    ######################################

         This subdirectory contains a set of script files that can be
         used to build the Tinker program package on a macOS system
         using GNU gcc/gfortran compilers under OpenMP parallelization.
         Early versions of the GNU compilers, in particular before 4.7,
         do not work correctly due to lack of support for some features
         of the OpenMP standard.

         Building reasonably portable executables requires linking with
         static gcc libraries. This can be done via use of versions of
         gfortran that enforce the -static-libgcc flag, or by copying
         the static libraries from the gcc directories into the Tinker
         build directory, as noted in "link.make".

         Alternatively, on macOS the shared versions, libquadmath.dylib
         and libquadmath.0.dylib, can be moved or renamed from within
         the directory containing the compiler libraries.

         If some or all of the executables fail via a segmentation
         fault, check the limits for your processes by issuing the
         "limit" command at the tcsh shell prompt (or similar under
         other shells). By default, these limits are set to quite small
         values. To eliminate the problem issue the following commands:

                        limit datasize unlimited
                        limit stacksize unlimited

         These same commands can also be put in your .tcshrc file or
         equivalent startup file to be run at login time.

