QE fix

[alberto-carta]

1) Modified energy calculation to be coherent with vasp:

First iteration:

• energy is read from the seedname.scf.out file

Subsequent iterations:

• Band energy is now read from the seedname.mod_scf.out file, and subtracted from the total energy.
• The correct band energy is read from the seedname.nscf.out file and added to the total energy

2) Manual compilation of the openmpi library to ensure PMI compatibility. This makes multi-node calculations viable on cray systems