I installed preCICE with MPICH since the website said OpenMPI does not currently fully support the MPI ports functionality. In case you link to OpenMPI, you cannot use MPI for the m2n communication of preCICE.
However, OpenFOAM needs OpenMPI for parallel computation. So I installed openFOAM with OpenMPI.
Will these two different ways of compiling affect the coupling of preCICE and OpenFOAM and parallel simulation?