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Messages - Dipankar Saha

Pages: 1 [2] 3 4 ... 35
16
Why so? Is it because of the volume (V) involved in KG ?
Yes.

So you mean, if one finds a rational for dealing with the volume term (specifically, the out-of-the plane axis), then KG can also be used for calculating optical spectrum (reasonably accurate) of any 2D material.

I don't think it's correct. So out-of-the plane axis is not the only concern. 


17
General Questions and Answers / Hybrid DFT SCF Loop
« on: March 22, 2019, 15:36 »
Hi,

1) what is meant by_ "no. of exact exchange iterations" ?
2) what is meant by_ "no. of exact exchange operator updates" ?

Best_
Dipankar

18
The Optical Spectrum analysis object of QuantumATK is not meant to be used for 1D and 2D materials - only for 3D bulk materials.

Why so? Is it because of the volume (V) involved in KG ?

One may also want to use a hybrid functional approach such as HSE to correct for single-particle excitation spectrum, but one do not account for two-particle excitation, e.g., excitonic effect.
What did you mean by saying_ "such as HSE to correct for single-particle excitation spectrum, but one do not account for two-particle excitation" ?

Thanks and Regards_
Dipankar Saha


19
Hi,

@ ATK (using KG formula):

1) How correct is the Optical Conductivity calculation,  for a 2D monolayer TMD (semiconducting)?
2) What does the optical spectrum portray, when it does not capture the many-body effects?

Best_
Dipankar Saha

20
General Questions and Answers / Angle between two bonds
« on: February 26, 2019, 08:15 »
Hi,

1) How can we measure the angle between two bonds?

2) @ ATK_
     do we have hybrid methods like B3LYP?

Best_
Dipankar 


21
General Questions and Answers / Re: NEB image
« on: February 12, 2019, 12:27 »
Okay, I understand .... Thank you Daniele !

22
General Questions and Answers / NEB image
« on: February 12, 2019, 08:44 »
Hello,

Is it possible to import any 'NEB image' to the 'Builder'?

Best_
Dipankar 

23
General Questions and Answers / Re: Initial Density
« on: February 9, 2019, 07:40 »
Okay.... Thank you  Petr!  :)

24
General Questions and Answers / Re: Initial Density
« on: February 8, 2019, 16:02 »
What is the role of 'Electrode Constraint' ?? 

25
General Questions and Answers / Initial Density
« on: February 8, 2019, 16:00 »
Hi,
@ Device Algo. _ Initial Density:
What's the difference between  the types 'Neutral Atom' and 'Equivalent Bulk'?

Best_
Dipankar

26
General Questions and Answers / Re: Plane-wave_HSE06
« on: January 30, 2019, 12:23 »
Okay, I understand! .... Thank you  :)

27
General Questions and Answers / Plane-wave_HSE06
« on: January 30, 2019, 09:25 »

Hi,
Do you have any tutorial which shows results calculated using  "ATK-DFT Plane-wave_HSE06"?

What is EXX operator ?

Best_
Dipankar

28
General Questions and Answers / Re: dft_half_parameters
« on: January 24, 2019, 10:39 »
Okay... Thank you! :)

29
General Questions and Answers / Re: dft_half_parameters
« on: January 24, 2019, 07:26 »
   
.......................
.......................
atomic_species="s2p2d1",
    hubbard_u=[0.0, 0.0, 0.0, 0.0, 0.0]*eV,
    dft_half_parameters=Automatic,
    filling_method=SphericalSymmetric,
    onsite_spin_orbit_split=[0.0, 0.0, 0.0, 0.0, 0.0]*eV,
    pseudopotential=NormConservingPseudoPotential("normconserving/upf2/S_PBE13.upf.zip"),
.......................
.......................


30
General Questions and Answers / dft_half_parameters
« on: January 23, 2019, 13:02 »
Hi,
Even if I don't enable DFT-1/2, I find "dft_half_parameters=Automatic" in the script !!
Is it okay?

Best_
Dipankar

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