New user here! I have spent the last 2-3 days looking at the manual trying to assess whether GULP has all I need for my purposes, and it looks like it’s the case! Kudos for building and maintaining such a great software!
I have doubts about the use of “energy” as an observable, especially in conjunction with the “shift” keyword. I don’t really understand these two comments in example22 " […] get rid of the large core contribution by removing the number in front of the decimal place […] " and " […] uniform shift to the energies of all structures to remove the constant offset […] ".
I’ll make my case, so that maybe it will be easier for you to help me understand.
I’m planning to use CP2K for the ab initio data. Say that I get -32.7128736 eV and -31.8736453 as the total energy of my system for configuration 1 and 2, respectively.
- Which value would I use for the energy as an observable in the first and second structure, if I specify a “shift” value after the first structure?
- It is not clear to me what is the offset we are talking about, could you give me a clarification on that?
Thanks a lot,
Paolo Sebastiano Floris