I can't put my email here, but you can find me easily with a Google search. in some of the videos you will see references to my published work. many people contact me through other social networks
Can you explain what the keywords "GridX6 NoFinalGridX Grid6 FinalGrid6" are exactly used for, and when are they needed? I've seen them used in many inputs, and I know what they are theoretically for, but cannot find an explanation. Also, don't know if it has to do with the version of ORCA, I tried adding them some times for comparison and got errors and the calculations wouldn't run until I remove them all..
those keywords are no longer used in Orca5. now you have to use DefGrid1, 2 and 3. Grid is the size of the quadrature grid used to numerically integrate the exchange correlation potential in DFT. GridX is a grid for the RIJCOSX approximation that is used for numerically calculating the exchange matrix when you have hartree fock exchange, for example in hybrid functionals. the numbers like Grid6 mean finer more accurate grids when higher numbers are used. FinalGrid6 means use the same grid for the final single point SCF iteration, because the default is a lower resolution grid. NoFinalGridX is actually not supposed to be there, it is worsening the results, that was counterintuitive in the syntax of the program and I didn't know at the time. now with DefGrid2 I think other grids are set automatically. but you should consult the manual for these stuff because there are many options and I don't know exactly how everything works.
@@niconeuman Oh thanks! I think the fact that I started using Orca5 and I was seeing all these tutorials and input examples which included these keywords confused me. I'm actually using the RIJCOSX approximation, but I don't add Grid-related keywords with DefGrid? Should I? Do you think I could find improvement in my calculations? Or just the "standard" should work most of the time? Thanks again!
I think the default in Orca5 is DefGrid2, which is apparently more than enough for most purposes. The Grids in Orca5 have been improved to be more consistent, apparently, and they are also larger than before so that they don't introduce certain errors (that's what I read).
Dear Nicolas N. I am a newbie so I still do not understand clearly about your code. But I meet a problem when I re-write your code on my computer. I meet a problem is that my computer does not understand P at "%output Print[P-Basis]2". Can you help me explain it? and How I can address this problem?
Hi, you should check the Orca manual to see how exactly to write those commands. I think you used P-Basis, when it should have been P_Basis. But in the manual it is written correctly: %output Print[P_Basis]2 Print[P_MOs]1 end This is what I always use to be able to plot the orbitals in Chemcraft/Avogadro. Cheers!
Hi, for visualizing the molecules and the animations I used Chemcraft. The plots were done in PowerPoint, exporting figures from Chemcraft and drawing the lines representing the energies to an approximate scale.
Sir how can I get connect with you?
I can't put my email here, but you can find me easily with a Google search. in some of the videos you will see references to my published work. many people contact me through other social networks
Can you explain what the keywords "GridX6 NoFinalGridX Grid6 FinalGrid6" are exactly used for, and when are they needed? I've seen them used in many inputs, and I know what they are theoretically for, but cannot find an explanation. Also, don't know if it has to do with the version of ORCA, I tried adding them some times for comparison and got errors and the calculations wouldn't run until I remove them all..
those keywords are no longer used in Orca5. now you have to use DefGrid1, 2 and 3. Grid is the size of the quadrature grid used to numerically integrate the exchange correlation potential in DFT. GridX is a grid for the RIJCOSX approximation that is used for numerically calculating the exchange matrix when you have hartree fock exchange, for example in hybrid functionals. the numbers like Grid6 mean finer more accurate grids when higher numbers are used. FinalGrid6 means use the same grid for the final single point SCF iteration, because the default is a lower resolution grid. NoFinalGridX is actually not supposed to be there, it is worsening the results, that was counterintuitive in the syntax of the program and I didn't know at the time. now with DefGrid2 I think other grids are set automatically. but you should consult the manual for these stuff because there are many options and I don't know exactly how everything works.
@@niconeuman Oh thanks! I think the fact that I started using Orca5 and I was seeing all these tutorials and input examples which included these keywords confused me.
I'm actually using the RIJCOSX approximation, but I don't add Grid-related keywords with DefGrid?
Should I? Do you think I could find improvement in my calculations? Or just the "standard" should work most of the time?
Thanks again!
I think the default in Orca5 is DefGrid2, which is apparently more than enough for most purposes. The Grids in Orca5 have been improved to be more consistent, apparently, and they are also larger than before so that they don't introduce certain errors (that's what I read).
Dear Nicolas N. I am a newbie so I still do not understand clearly about your code. But I meet a problem when I re-write your code on my computer. I meet a problem is that my computer does not understand P at "%output Print[P-Basis]2". Can you help me explain it? and How I can address this problem?
Hi, you should check the Orca manual to see how exactly to write those commands. I think you used P-Basis, when it should have been P_Basis. But in the manual it is written correctly:
%output
Print[P_Basis]2
Print[P_MOs]1
end
This is what I always use to be able to plot the orbitals in Chemcraft/Avogadro.
Cheers!
@@niconeuman thank you so much for your help.
What visualization program did you use?
Hi, for visualizing the molecules and the animations I used Chemcraft. The plots were done in PowerPoint, exporting figures from Chemcraft and drawing the lines representing the energies to an approximate scale.