QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Luis M. Villamagua C. on January 14, 2014, 09:23

Title: Geometry optimization
Post by: Luis M. Villamagua C. on January 14, 2014, 09:23

After relaxing a 8-ZGNR of approx 2.8nm long (device) with DFT I was wondering in what way could I check if my optimization is ok. I compared the initial and the final coordinates, but I do not think that is all. Can you guide me please?.

Also, I unckecked "No SCF" for DFT. Is that correct?. In the tutorial online relaxation is carried out the Huckel model and they unckek it. I do not really understand why they do that.

Thanks in advance,
Luis

Title: Re: Geometry optimization
Post by: Anders Blom on January 14, 2014, 19:25

First of all, you can't actually use the Huckel method to optimize in ATK.

Second, the DFT calculation should always be self-consistent, so don't check this box. Some of the semiempirical models in ATK can be used non-selfconsistently for specific purposes.

Finally, you should check the log file to see that your optimization calculation converged (no warnings etc), and then inspect the geometry visually to see that it doesn't look weird. There is not much more to it :)