Mehcwn
I have just installed the Ubuntu 12.04 package and I have noticed that it's a serial nwchem binary,
not linked against MPI.
If you wish to avoid dealing with installation with the source code, you might want to install the Debian pkgs,
that 1) are linked against MPI and 2) are compatible (just tested) with the Ubuntu 12.04 software stack (MPI included).