QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: simCity on September 10, 2013, 12:25

Title: Simple optimization example
Post by: simCity on September 10, 2013, 12:25

Hi,

I'm trying to make an optimization to a graphene sheet with the code attached. However, there seems ony 1 optimization step even if I change the optimization force criteria from 0.05eV/A to 0.03 or 0.01. The initial atomic positions do not change after the code is run as you can see from the output file. Is there a problem with the code, your help is appreciated.

Thanks...

Title: Re: Simple optimization example
Post by: Anders Blom on September 11, 2013, 00:01

I don't think it will converge in 0 steps for a lower force criterion - your output file shows that the max forces in step 0 are about 0.04 eV/Ang. So, for 0.05 as criterion yes, but for a smaller value it should go on, and I don't see any output showing that it doesn't. But in general, I would not expect that a system like this exhibits any strong changes in positions. And besides - if you would want to optimize it, just optimize the C-C bond length in pure graphene (2 atoms) which is a lot faster, before you make the supercell.

Title: Re: Simple optimization example
Post by: simCity on September 19, 2013, 09:48

Thanks. It worked.