Linux PC clusters with MPI

PC clusters running some version of MPI are a very popular computational platform nowadays. Two major MPI implementations (MPICH, LAM-MPI) are available. The number of possible configurations, in terms of type and version of the MPI libraries, kernels, system libraries, compilers, is very large. Quantum-ESPRESSO compiles and works on all non-buggy, properly configured configuration. You may have to recompile MPI libraries in order to be able to use them with the Intel compiler. See Axel Kohlmeyer's web site for precompiled versions of the MPI libraries.

If Quantum-ESPRESSO does not work for some reason on a PC cluster, try first if it works in serial execution. A frequent problem with parallel execution is that Quantum-ESPRESSO does not read from standard input, due to a bad configuration of MPI libraries: see section ``Running on parallel machines''. If you get weird errors with LAM-MPI, add -D__LAM to preprocessing options and recompile. See also Axel Kohlmeyer's web site for more info.

If you are dis satisfied with the performances in parallel execution, read the ``Parallelization issues'' section.