Bader charges computations

[sitangshu]

Dear Quantumwise,

I see that in the feature list at
http://quantumwise.com/products/features
there is an option to analyze the charge transfer procedure through Bader's method.  We are using currently 2014.1 version. Is it included as "charge" in FHI-AIMS of this version or should I download the 2015 version?

[Umberto Martinez]

NO, you can use VNL and ATK 2014. However, please update to the latest release 2014.2 which you can find on our website available for download.

[Dipankar Saha]

Dr. Umberto Martinez,

1) Being Full-potential in all electron scenario....how do you tune the "Accuracy"  (as, we find medium to ultra...with Tier 1 to Tier 3) ??
2) What if, in a composite-system... one of the materials is metallic and the other one is Insulator ?!!

Regards_
Dipankar

[Dipankar Saha]

Besides,  I wanted to know_

Has there any VW correction for PBE (such as, Tkatchenko-Scheffler interatomic dispersion .....) been implemented as of now??

[Jess Wellendorff]

I believe your questions are related to the FHI-aims calculator.

We should take great care not to confuse ATK with FHI-aims. ATK is a platform that includes several different computational engines, including ATK-DFT, ATK-semiempirical, and ATK-classical. FHI-aims is another engine for first principles calculations, developed at the Fritz-Haber Institute in Berlin. You can set up, run, and analyze FHI-aims calculations using the VNL interface, but your ATK licence must include access to FHI-aims for this to work.

1) FHI-aims accuracy is tuned mainly by increasing the basis set size and by using increasingly dense integration grids.
2) What matters is the expected electron distribution around the Fermi level of the full system, not the individual parts of it. Is the full system an insulator or conductor? In any case, both options may often work rather well.
3) ATK offers the Grimme DFT-D method, while FHI-aims also implements the TS and vdW-DF methods for van der Walls interactions.

[sitangshu]

Dear Jess,

Thanks for your reply. Incidentally, we are studying the interface of semiconductor/insulator/amorphous metal oxide. It seems the DFT procedure is working well for charge distribution analyses.

[nahid khadempar]

hello,good time..
 excuse me , I cant find any Information about the Conversion between hexagonal and
 simple orthorhombic settings....please guide me..thanks for your help.

[Anders Blom]

See http://quantumwise.com/publications/tutorials/item/99-commensurate-supercell-for-rotated-graphene-layers

You could also try https://www.google.com/search?site=&source=hp&q=transform+hexagonal+cell+to+orthorhombic+in+virtual+nanolab&oq=transform+hexagonal+cell+to+orthogonal+supercell+in+virtual+nanolab

Searching is often quicker than asking

[Dipankar Saha]

Thank you very much  Jess ...!!!  / Yeahhh...I already knew the license isuue ....

All I was  wondering about the  O (N) scaling ...instead of O (N³) ...!!! Would it allow me to use large no. of atoms?

I got your points..what you have mentioned otherwise..!!!

Regards_
Dipankar