CMake will set the defines MPI_FOUND and BOOST_MPI_FOUND if the
corresponding files were found during configuration
the code has some (not too many, thankfully) new #ifdef instructions
for the preprocessor, so that lines are excluded if the defines are
not set.
in CMakeLists.txt, the files calc_phi_ase_mpi.cc and
calc_phi_ase_graybat.cc are removed from the project if the
requirements are not fulfilled, so they are not built
CMakeLists.txt
, the filescalc_phi_ase_mpi.cc
andcalc_phi_ase_graybat.cc
are removed from the project if the requirements are not fulfilled, so they are not built