| 2:11:58 PM PDT - Mon, Jul 7th 2014 |
|
Well, that didn't work. GAMESS-US and Firefly have diverged more than I thought.
After some reading and looking I noticed your "freeze core" directive. This doesn't actually do anything -- you need to put a greater-than-zero number after "core" for it to have an effect, e.g. "freeze core 1".
I read the Gaussian manual about frozen cores and there sure are a lot of options! I don't know if NWChem's "freeze atomic" is equivalent to the default Gaussian freezing scheme for post-HF calculations, but it's worth a quick try.
If the results still don't match it is time to carefully read your Firefly and NWChem output files side by side. Are the numbers of orbitals and basis functions the same for both calculations? Do the energies for SCF and MP2 agree to a reasonable number of decimal places? You may also want to manually compare the basis set definitions that are echoed in the output files. You would think that the definition of "6-31G**" was set in stone long ago, but I have been surprised in the past to find how software has interpreted named Pople basis sets.
The earliest significant numerical divergence between the two jobs needs to be corrected or explained before downstream results. If everything agrees closely except the final cube, that would be surprising.
|