Messages

1

General Questions and Answers / Re: silicone Quantum Espresso.in related query

« on: November 2, 2018, 18:09 »

Dear Mr  Petr Khomyakov,
I completely understand what you are trying to mention.In that case I have just two queries
1.Is there any ready made silicene structure in quantumwise library like Graphene with which I can directly start my calculation?
2.If I do not buckle the structure ,just replace the Graphene atoms with silicon.In that case will the hexagonal symmetry be unaltered?
I am looking for a solution.

Thanks and regards,
Anindya Bose

2

General Questions and Answers / Re: silicone Quantum Espresso.in related query

« on: November 2, 2018, 15:14 »

I forget to mention one more thing , I rattled the structure too to create buckling.However nothing rectified the point group symmetry error.Please suggest me what to do?

Thanks and regards,
Anindya Bose

3

General Questions and Answers / Re: silicone Quantum Espresso.in related query

« on: November 2, 2018, 14:52 »

I Started by adding graphene  from the Database to the Stash.
Change the two atoms to Si by selecting them and use the Periodic Table tool change_element .
The lattice constant of silicene is not the same as for graphene, I set it to 3.8 Å, otherwise the forces will be too large in the beginning of the optimization. Also increase the C lattice constant to 20 Å (in both cases making sure to keep the fractional coordinates fixed). Therefore the structure was taken in centre by using coordinate tool.Later I export this structure by espresso.in format and processed it.But relax.out doesn't show the correct point group symmetry.

Thanks and regards,
Anindya Bose

4

General Questions and Answers / silicone Quantum Espresso.in related query

« on: November 2, 2018, 11:33 »

Dear Experts,
I have created the unit cell of silicine by altering the unit cell of Graphene as suggest by the method  proposed in VNL ATK tutorial.But unfortunately I don't find the hexagonal point group symmetry in relax.out file of silicine.But for Grapheme I get the correct symmetry (D6h) and for silicene it is the same.Is it a major drawback of VNL ? No direct structure of silicene is not provided VNL.How can I resolve the issue?

Thanks and regards,
Anindya Bose
Research Fellow,
IIIT Allahabad

5

General Questions and Answers / Re: Issue related to Graphene script in espresso.in format

« on: September 12, 2018, 14:38 »

Dear Expert,
Will the 2018 version. solve this vc-relax issue surely?

Thanks and regards,
Anindya Bose

6

General Questions and Answers / Issue related to Graphene script in espresso.in format

« on: September 12, 2018, 08:06 »

Dear Experts,
I am using VNL ATK 2015 version and I am facing some peculiar problem with Graphene script in espresso.in format.First I create the Graphene structure(unit cell of 2atoms) in Quantumwise which consists off 10 ang vacuum in z direction to avoid the problem of periodic replicas. After that I export the structure in espresso.in format.When I perform vc relax on this I see the hexagonal symmetry of graphene breaks.Instead of giving actual symmetry of Graphene which is D_6h(point group), the output file gives D_2h(an erroneous value).I don't understand why this is happening.After vc-relax the structural symmetry of an intrinsic material should not be changed under any circumstances.Please tell me how to resolve this issue.Do I need to do anything else to make this effective.Please help.

Thanks and regards,
Anindya Bose
Research Fellow,
Indian Institute of Information Technology, Allahabad

7

General Questions and Answers / Adding vacuum in monolayer structure

« on: March 6, 2017, 08:17 »

Dear Sir,
Is there anyone who can tell that how can I add 20A vacuum layer in monolayer WSe2 structure using Quantumwise.Where I can get this option?

8

General Questions and Answers / Re: Problems regarding interface simulation using non collinear spin orbit(SOGGA)

« on: February 2, 2017, 07:26 »

please find the file attached with

9

General Questions and Answers / Problems regarding interface simulation using non collinear spin orbit(SOGGA)

« on: January 31, 2017, 14:06 »

I am not getting the band diagram file while doing the calculation through non collinear spin orbit(SOGGA),is there anyone who can help me to solve this problem.I have enclosed the log file with it.

10

General Questions and Answers / Re: Quantum wise related problems

« on: January 19, 2017, 05:49 »

I have enclosed the log file also here.I am not getting any .nc file.

11

General Questions and Answers / Re: Quantum wise related problems

« on: January 19, 2017, 05:46 »

Dear Sir,
I have enclosed the python script here.Can you please look into this.

12

General Questions and Answers / Quantum wise related problems

« on: January 18, 2017, 08:32 »

Dear Sir,
I am using Quantumwise version: Virtual NanoLab 2015 and during the time of GW calculation in new calculator under FHI AIMS option I am not getting any .nc(Net CDF) file, without it I can't get any output curve(band structure, DOS etc). How can I solve this problem? Is there anyone who can tell me that how can I perform GW calculations in Quantumwise.