@paulromano I think all the code before the MPI_BCAST should just be the master only.  k_generation is undefined for processors other than master. When running with gfortran in DEBUG mode with HDF5 and MPI I get an erroneous operation error. When I put an if(master) around everything before the MPI_BCAST, this error goes away and I get the same results. I didn't make the commit myself in case you wanted k_generation to be defined on all processors.