Hello. I'm a beginner of the dft from PNU, South Korea undergraduated student and tying to calculate binding energy. actually i have a question
which is that for the binding energy calculation I can get the BSSE energy and complexation energy(corrected) In gaussian 16rev singlet point energy calculation using cunterpoise=2(which is binding energy). but I wanna do the same work in the orca. is there any way to get the BSSE energy and complexation energy in orca?
I really appreciate for answering to undergraduated student's question in advance.
Hello Lee Taekgi
Please refer to the 6.1.6. Counterpoise Correction section of the orca 6 manual: https://www.faccts.de/docs/orca/6.0/manual/contents/typical/energygradients.html#counterpoise-correction
The above procedure will give you the interaction energy. You need not do the steps mentioned in the manual; they have a compound script for it. They have given the location of the compound script in the manual.
Feel free to ask more questions; I'm glad to answer.
Regards,
Dilawar
Dilawar Singh Sisodiya Thank you for having an answer for my question. And I'm wondering if I can have one more question about BSSE.
From your advice I did some BSSE Calculation for my system which has Cluster (containing Ti, Mg, C, O) and Hydrogen, Center of hydrogen is from 2.5 Armstrong to 5 Armstrong. Among these cases I can get converged value generally but for the particular case like 2.7, 3.8, 4.4 (maybe 7 cases per 26 cases) have can not make convergence.
My first trial was without SCF options and Second trial was using command "!NoTRAH KDIIS SOSCF" and the results came out. but the result looks it doesn't make sense. (I will add my result data which shows 3 local minimum in the graph) the same calculation from gaussian 16rev looks it makes sense
So, I'm trying to do ConvForced Keyword from Orca Manual. But I don't know much about this command and do you think this command will get results better?
Hello Lee Taekgi
For the convergence problems, you may try changing the number of cycles or tolerance for other parameters as described in the manual. Getting SCF convergence problems can be frustrating; it happens to me.
I suggest that you check the part where it is failing. You can also try to read MOs from the successful calculation.
Reading MOs does help.
From what I understand, the "ConvForced" keyword is used when, let's say, we want to avoid the non-converged SCF and do the next calculation steps.
You may want to have SCF convergence for all of your calculations. Try to avoid using this keyword.
If you can let me know more details about the SCF part, I can try to help more.
Regards,
Dilawar
Dilawar Singh Sisodiya Let me look for more information about the SCF Errors. Thank you for answering again !
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