Topics

16

General Questions and Answers / LDA+U with OpenMXBasisSet

« on: April 22, 2016, 17:21 »

Hi All,

If we want to do LDA+U calculations using OpenMXBasisSet in ATK, how do we adjust the script to include the hubbard U parameter in basis set?  (demonstration for NiO or CuO shall be fine).

In tutorial http://quantumwise.com/documents/tutorials/latest/NiO_LDA_U/index.html/chap.crystal.ldau.html
FHI basis sets are used.

Thank you.

Regards,
Yasheng

17

General Questions and Answers / Geometry optimization in Extended-Huckel method.

« on: April 22, 2016, 15:10 »

Hi,

When I tried to do geometry optimization with Extented-Huckel method for copper, the word 'OptimizeGeometry' on the script generator appeared as 'OptimizeGeometry'. Does this mean that we cannot do geometry optimize with Extended-Huckel method in ATK?

Regards,
Yasheng

18

General Questions and Answers / LDA+U in ATK

« on: April 16, 2016, 22:41 »

Hi,

I have some problems with setting up calculations for Cu/Cu2O interface. I want to disable Hubbard U for metallic Cu while I want to use Hubbard U for the Cu atoms in Cu2O.  Can you please give some advice on how to do it?

Regards,
Yasheng

19

General Questions and Answers / question about tutorial

« on: April 12, 2016, 11:32 »

Hi,

I have question about the tutorial on this page:
http://quantumwise.com/publications/tutorials/item/832-elastic-scattering-mean-free-path-mobility-impurity-scattering-in-a-silicon-nanowire

I wonder how can you get one combined nc file for four different calculations.
(dopant 1, dopant 2, dopant 3 and dopant 4 has one nc file named sinw_transmissions_P_dopant_1_2_3_4.nc).

Thanks for your explanation.

Yasheng

20

General Questions and Answers / stoping ATK job

« on: February 23, 2016, 15:45 »

Hi Everyone,

I wonder if there is anyway to stop ATK DFT geometry optimization job just after the coming Force step finished.   Similar thing can be done by using STOPCAR in VASP. 

Thanks,
YM

21

General Questions and Answers / Can we do the geometry optimization and transport properties in one calculation?

« on: February 10, 2016, 11:55 »

Hi All,

Should we first do the geometry optimization, then take the optimized structure to calculate the transport properties?

or

Should we do everything in one calculation?

Thanks.

22

General Questions and Answers / Charged system

« on: February 8, 2016, 13:25 »

Dear All,

I am a new user of Quantumwise, and I have some questions about charged system. I saw some posts about charged system in this forum, but it is not very clear for me how exactly to do it.

(1) first of all, where we can see the number of electrons in the system?

(2) if we want add charge q=-1, or q=+1 to the system, how do we do it?

Thank you,
Yasheng
 

23

General Questions and Answers / configure remote PBS in job manager

« on: January 6, 2016, 17:02 »

Hi All,
I want to submit job from local machine to a remote cluster, but I have some problem with configuring the remote PBS. I understand that we can do it by creating a remote PBS in job manager. I went to job manager > machine manager > new remote PBS. Then I have trouble there.

How do we fill all these sections after that ?
Is it possible to  complete all these sections according to the PBS scripts to submit jobs in the cluster?

Your explanation is most welcome. Thanks.

Regards,
Yasheng

24

General Questions and Answers / nanowire and surface energy

« on: November 4, 2015, 10:58 »

Dear All,
I have question about building nanowire using VNL. In order to build nanowire of a fcc metal, we need to choose wire direction and surface energies of (100), (110) and (111) surfaces. The default values for these surface energies are 1 eV.
First of all, this is little bit misleading: the units of surface energy should be eV/A^2 or J/m^2. I checked the tutorial about building Si nanowire. It says we need to provide relative surface energies. What does the relative surface energy mean ?

For example, the surface energies of copper surfaces calculated with PBE are as following

Surface energy of Cu(100) = 1.442 J/m^2
Surface energy of Cu(110) = 1.532 J/m^2
Surface energy of Cu(111)  = 1.273 J/m^2

If we want to build a copper nanowire, what values of surface energies should we provide in nanowire builder?


Please response if you know the answer. Thank you for your help

Best regards,
Yasheng