In the output result, I found that HOMO and LUMO energies were too high. I wonder what is the problem in here.
Please check attached files.
In first file, NPREO was used to print homo-1, homo, lumo, and lumo +1. Second file contains all MO values.
Calculation is performed in PM6.
Please share with me if you have any idea.
If energies are converted to eV from Hatree, then HOMO and LUMO will be 27.86 eV and 30.52 eV, I think these are unrealistic values for drug molecules.
Pritam Kumar Panda
Could you please tell me little bit more what ArgusLab is?
Pritam Kumar Panda
Thanks for your suggestion. I have found out that ArgusLab offers three semi-empirical methods. Currently, I'm looking for semi-empirical method that covers metals too, so I think it's difficult to use ArgusLab in my project. :(
1. May be you not reach to the right minimum energy by optimization.
2. Remember the value for individual molecule.
3. The value depend on method of calculation
4. The best method is DFT or HF.
Falah is correct: your structure is in fact not fully optimised.
I just plopped your geometry into MOPAC (http://openmopac.net/) and it went through 349 optimisation cycles until it found the ground state structure.
The output is attached.
He is also correct that DFT or HF are better methods to get good values for orbital energies, as semiempirical methods such as PM6 make a lot of approximations there.
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