Can you send the output of:
For the MP library, instead of -lacml, you must use -lacml_mp.
However you have not specified openmp in your build command so this case you should not use the openmp ACML. Use instead -L/opt/acml4.4.0/gfortran64/lib -lacml.
One other observation - you are building an mpi application. When you are using threading at the application level, either with OpenMP or MPI, we generally recommend using the single threaded ACML. When threading is used in the application, and by the library, thread oversubscription can occur.
It is possible to use the OpenMP ACML with MPI for the application, for instance for HPL builds. But usually this results in lower performance.