Hi Derek,
We currently use VASP to relax our molecules down to 0.01 eV/Ang. However,
we do this for the experimental structure before engaging in both volume and
uniaxial compressions. For the compressions experiments, we generally like
to relax to 0.03 eV/Ang; however, at some point ionic convergence just
doesn't want to happen down to 0.03. In such cases we do everything we can
to get convergence down to 0.05 - this we tend to deem publishable. Of
course, we are currently trying to match our Siesta results to our VASP
results with no success. If you end up successful in your endeavor, I would
be very interested to know what parameters you had to adjust. Good Luck
with your research!
Aaron
From: "Derek A. Stewart" <[EMAIL PROTECTED]>
Reply-To: "Siesta, Self-Consistent DFT LCAO program,
http://www.uam.es/siesta"; <[EMAIL PROTECTED]>
To: [email protected]
Subject: [SIESTA-L] Defining an acceptable force tolerance for Siesta
Date: Mon, 6 Aug 2007 11:07:58 -0400
Hi everyone,
I wanted to get the Siesta community's perspective on what is an
acceptable tolerance for the maximum force during a structural relaxation
tolerance. I know the default for the program is 0.04 eV/Ang, but I have
seen several papers that use lower force tolerances. Would this imply
that some papers using the default 0.04 eV/Ang tolerance are not converged
enough? Are there specific systems where more care is required?
Thanks,
Derek
################################
Derek Stewart, Ph. D.
Scientific Computation Associate
250 Duffield Hall
Cornell Nanoscale Facility
Ithaca, NY 14853
