Messages

1

General Questions and Answers / Re: Poisson solver

« on: October 30, 2017, 21:59 »

Dear ATK-developers,

I want to know the effect of poisson solver and periodic condition, so i did the several calculation of MoS2 monolayer.
MoS2 monolayer created by removing one unit of MoS2 from bulk and optimized it. here, i have considered periodicity in A and B direction and 25A vaccum created in C direction.
computational details are
K points (10x10x1)
GGA-BPE
LCAO-DZDP and remaining by defaults parameters considered.
total energy of MoS2 (unit cell) monolayer are
E = -1176.97 (FFT2D with dirichlet BC)
E = -1177.17   (multigrid with neumann)
E= -1176.98  (FFT with periodic BC)

I read from the previous post that milti-grid  used for device application.
So, Please explain me in details about the poisson solver and boundary condition.
what poisson solver and BC should use for 2D monolayer.
 

2

General Questions and Answers / Re: the formation energy defect of BaZrS3 perovskite

« on: October 10, 2017, 15:19 »

because many researchers reported that 4x4 supercell is more than sufficient.

3

General Questions and Answers / Re: the formation energy defect of BaZrS3 perovskite

« on: October 6, 2017, 15:38 »

I am using a 4*4*1 supercell, So i think it is not a too small supercell

4

General Questions and Answers / Re: the formation energy defect of BaZrS3 perovskite

« on: October 5, 2017, 15:44 »

Dear Petr,

I did the calculation by considering the vacancy of atom as a ghost atom but the problem could not be resolve. you have any other suggesting to find the accurate computational result. because your tool results challenge the experimental and other computational results.
 Thank you and waiting for your kind response.

5

General Questions and Answers / Re: the formation energy defect of BaZrS3 perovskite

« on: October 5, 2017, 10:38 »

Dear Petr,

I am computing the result by considering the ghost atom but can you give me detailed explanation about this ghost atom? what are the limitation of ghost atom? and where it is used? and also send me a link of reference paper of ghost atom.

Thank you.

6

General Questions and Answers / Re: the formation energy defect of BaZrS3 perovskite

« on: October 3, 2017, 10:21 »

Yes I have checked all the steps and vary the basis sets and exchange correlation potentials but found the same trend. that is why i have doubt in this calculation

7

General Questions and Answers / Re: the formation energy defect of BaZrS3 perovskite

« on: October 1, 2017, 09:01 »

Dear ATK developers,
you have any explanation about my  previous question.

Thank you

8

General Questions and Answers / Re: the formation energy defect of BaZrS3 perovskite

« on: September 29, 2017, 13:58 »

Dear Sir,
Formation energy of ZnO_Ov should be smaller than ZnO_Znv but in my case i found the opposite result means formation energy of ZnO_Ov larger than ZnO_Znv that is absolutely wrong.
you can read this paper http://www.sciencedirect.com/science/article/pii/S1567173912004889
this paper did the whole calculation using Wien2K and found that the formation energy ZnO_Ov < ZnO_Znv.

9

General Questions and Answers / Re: the formation energy defect of BaZrS3 perovskite

« on: September 29, 2017, 07:51 »

Dear Sir,

I have also a problem in the formation energy of defected ZnO monolayer.
Here, I have computed the formation energy of oxygen vacancy in ZnO monolayer (ZnO_Ov) and zinc vacancy in ZnO monolayer (ZnO_Znv) using the https://docs.quantumwise.com/tutorials/formation_energies/formation_energies.html tutorial. and found that ZnO_Ov has more formation energy than ZnO_Znv that is absolutely wrong.
Computational details which i have used are
GGA-PBE with double zeta double polarized and 6x6x1 k points
force convergence criterial = 0.001

result i obtained
ZnO (Pristine) = 31662.38 eV
ZnO_Ov = 31226.73 eV
ZnO_Znv = 30113.38 eV
Zn = 1541.73 eV
O = 427.81 eV

Ef (ZnO_Ov) = 7.83 eV
Ef (ZnO_Znv) = 7.26 eV

10

General Questions and Answers / Re: optical properties

« on: July 23, 2015, 06:09 »

Dear Staff Members,

Please respond me as soon as possible....

11

General Questions and Answers / Re: optical properties

« on: July 13, 2015, 09:34 »

Dear ATK staff member,
 
will you able to explain my problem? please respond me ....

12

General Questions and Answers / Re: Magneto-optical properties

« on: July 13, 2015, 09:32 »

Dear ATK staff member,
 
will you able to explain my problem? please respond me ....

13

General Questions and Answers / Re: Magneto-optical properties

« on: July 12, 2015, 08:56 »

any one are able to give me solution of this problem ...plz

14

General Questions and Answers / Re: optical properties

« on: July 12, 2015, 08:54 »

can  any one help for resolving the problem  ......

15

General Questions and Answers / Magneto-optical properties

« on: July 9, 2015, 08:37 »

Dear Sir,
Can I find the magneto-optical properties in terms of kerr rotation and kerr ellipticity of the heusler alloy through the ATK? .... if  it is possible then please share me idea about that ...