Prerequisites

1. mpshift needs converged MO vectors from a SCF or DFT run (dscf or ridft)
2. for SCF or DFT calculations, no specifications have to be made in the control file
3. it is not possible to run the program in the fully direct mode when doing an SCF, MP2 or a DFT (using hybrid functionals) run, so you will have to perform a statistics run of dscf before calling mpshift, or just set the size of the $twoint file to a non-zero value
4. to perform an MP2 calculation of the NMR shieldings you have to prepare the input with mp2prep -c