1) Go to https://github.com/ondrolexa/Perple_X/releases, download the latest release
   and extract the files to a directory of your choice.

2) The executeable binaries and data and option files are in seperate subdirectories,
   it is easiest to use Perple_X if the files are copied to their parent directory, 
   i.e., the directory chosen in step 1.

3) Run Perple_X programs from a shell (aka terminal window). Configure the shell 
   so that the directory in step 1 is the default current working directory.

4) Follow the remaining instructions at 

   www.perplex.ethz.ch/perplex/ibm_and_mac_archives/README_COMMON_INSTRUCTIONS.txt

5) To compile your own version of Perple_X, install a Fortran compiler such as gfortran.
   Change directory to the src subdirectory and verify that the makefile has the correct 
   compiler options for your system. Then type make all.