Notes on running GDMA

The gdma2_MP2.dat file given here is set up to extract the distributed multipoles from an MP2 wavefunction. If you are using any other quality of wavefunction, you need to remove the line that says "DENSITY MP2" from the file. All other qualities of wavefunction (including SCF within an MP2 calculation) write the charge density to the same place in the file, and it is only the MP2 charge density that is written to a different place.

FILE specifies the GAUSSIAN output that is to be read in.

"Limit 4" instructs the programme to write multipoles up to level 4. Sometimes, "Limit 1 H" is included, which is the instruction to only use dipoles on hydrogen. This has been shown not to give as accurate an answer as "Limit 4" for all atoms, and the cost-saving is not worthwhile. In the group at UCL, we use "Limit 4" on all atoms.

"Punch" gives the name of the output .dma file, and can be changed to anything appropriate.