Exploring the ever ending alternatives regarding generation RESP charges I found a number of things peculiar and I though I’d ask.
One example I found in the tutorials was the following:
#P HF/6-31G* SCF=Tight Pop=MK IOp(6/33=2,6/41=10,6/42=17)
I suppose that the 41/42 are not set in stone and can be changed? However, I cannot find the documentation for 6/33=2, as it reads “do not change” I assume it is important though is this still applicable or has this changed?
Another suggested example which does work with antechamber:
#p b3lyp/6-31G(d,p) nosymm iop(6/33=2) pop(chelpg,regular)
Based on this, I suspect that while not documented, the "6/33=2” option still applies? As defaults are used for fit options, these can be changed?
This made me curious regarding the use of Pop=MK, as this was not suggested by the second source using B3LYP. Reading a bit further about MK it includes 6/50=1 producing files for RESP generation. This made me curious, there seems to be no need for these files which can be generated as the output produced using either of the above suggested seems to work just fine.
As I am unable to figure out how to actually get this file written, this might be a good think. Assuming that this would work, "using Pop=MK IOp(6/50=1) and specifying the file name on a separate line at the end of the Gaussian input file.” (which I am unable to get to work), how would the produced file be used together with antechamber? Would this mean providing a structure file (pdb) instead of the gaussian log file and using the -ge option.
I suppose what I am asking (except regarding 6/33=2), is there a best practice for generating RESP charges using gaussian and antechamber? This includes if one should indeed use Pop=MK and if using the log-file is acceptable or if I should try to figure out how to use the 6/50=1 option. What (if anything) should be considered as non-optional input?
Best regards
// Gustaf
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Received on Wed Apr 28 2021 - 04:00:02 PDT
