Andreas
Your output shows some leftovers from the OpenMPi compilation.
I would do the following:
1) change the MPI_LIB definition to (i.e. delete the first -L)
MPI_LIB="/opt/intel/impi/5.0.1.035/intel64/lib/release -L/opt/intel/impi/5.0.1.035/intel64/lib"
2) cd $NWCHEM_TOP/src/tools
3) rm -rf build
4) make FC=ifort
5) cd ..
6) make FC=ifort link