Messages

931

General Questions and Answers / Re: The iv curve calculation did not converge to the requested tolerance!

« on: May 19, 2015, 13:40 »

No, the calculation will always proceed even though the SCF loop did not fully converge. We believe that in most cases this is more of an advantage than a disadvantage.

932

Scripts, Tutorials and Applications / Re: The computed multigrid residual is greater than the required accuracy

« on: May 18, 2015, 17:27 »

Hi there!

The problem is that the two metallic regions on top and below the dielectrics in your device are too thin. If you increase the thickness of both metallic regions from 0.1 Å to at least 1.0 Å, the problem disappears.

The reason is that the Multi-grid Poisson solver does not work well when the metallic regions become extremely thin (e.g. 0.1 Å, less than a monolayer of metal).
You could also consider using the Direct solver, which does not rely on iterative solution of the Poisson equation. That algorithm uses significantly more memory, but might be more efficient if your calculation uses many SCF steps.

933

General Questions and Answers / Re: constraint a dihedral angle

« on: May 18, 2015, 15:25 »

Dear Amir,

unfortunately we do not currently support such constraints during geometry optimization. Fixed atoms and rigid regions are the only options.

Best,
Jess