Messages

1

General Questions and Answers / Re: Total dipole moment

« on: October 13, 2017, 12:23 »

Hi,
The link to the script to calculate dipole moment is not working. It takes to the atk manual. Is it possible to share it?

2

General Questions and Answers / Re: Band decomposed charge density

« on: May 5, 2017, 01:12 »

I need a precise definition of the BlochState. Is it only the envelope part of it?
psi_nk(r)=u_nk(r)exp(ik.r)

Is BlochState u_nk(r) ?

3

General Questions and Answers / Re: Band decomposed charge density

« on: April 21, 2017, 16:18 »

Thanks Petr.

Is the BlochState normalized?

4

General Questions and Answers / Re: Band decomposed charge density

« on: April 20, 2017, 10:40 »

Thanks Petr for you reply. It satisfies my DOS query.

In the BlochState approach, I am wondering if the class BlochState has any method to return energy value of the quantum number it takes as an input. Quantum number is a band index right?

5

General Questions and Answers / Re: Band decomposed charge density

« on: April 19, 2017, 13:30 »

Thanks Petr,
I had gone through the posts. However, the approach is still not clear. I have few questions.
In the BlochState approach, the quantum_number argument to BlochState function is the band index, right? Can you please clarify.

I would also like to compare two approaches, 1) The BlochState approach and 2) The loca density of states approach, LDOS.

In the LDOS approach, if you follow second part of my opening comment, 'Zh' suggests that only summing up LDOS would give you band decomposed electron density. But I think LDOS x Fermi function to be summed up. Can you please clarify?

6

General Questions and Answers / Band decomposed charge density

« on: April 19, 2017, 07:48 »

Hi,
I want to calculate the band decomposed charge density. For example, if I simulate silicon bulk using ATK-DFT then after that I want to calculate electron density (or charge density) in each valley of silicon (Delta and Gamma). I have checked this link http://quantumwise.com/forum/index.php?topic=1356.0 . But that is relevant for DeviceConfiguration. I have a BulkConfiguration. Is there anything similar for the bulk configuration?

 Also in the second comment (from Zh)
"The concept of the partial charge density of a given band or eigenvalue is basically the same as the local density of states.
http://quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.localdevicedensityofstates.html
The summing up the the local density of states for the eigenvalues at a specified band will give the band-decomposed partial charge density."
don't you think that just summing up ldos won't work in the conduction band. One has to sum up ldos x fermi function, no?

7

General Questions and Answers / Re: Plotting pseudopotential potential

« on: January 19, 2017, 19:33 »

Gentle Reminder.

8

General Questions and Answers / Plotting pseudopotential potential

« on: January 19, 2017, 06:15 »

I want to plot pseudopotential contribution to the effective potential. The method ExternalPotential returns zero at all grid points. According to the background information it should be the part of external potential.

How do I get this contribution?

9

General Questions and Answers / MGGA formulation

« on: November 23, 2016, 16:23 »

In the original paper from Tran and Blaha, they use sqrt(5/12) factor. But QuantumWise is using sqrt(4/12) factor in their formulation http://docs.quantumwise.com/tutorials/inas_2d_mgga/inas_2d_mgga.html.
Which is the implemented version?

10

General Questions and Answers / Re: Bug in labfloor update

« on: September 14, 2016, 14:32 »

I guess I have found the cause. I generally use emacs editor to edit the .py files. Sometimes the editor creates hidden files starting with a dot (.) . When I remove these hidden files, the labfloor updates smoothly.

11

General Questions and Answers / Re: negative DOS below the valence band

« on: May 19, 2016, 19:02 »

Below -10eV, there is only one band, and if you look at the Fig 3 of this paper http://dx.doi.org/10.1103/PhysRevB.80.115205, it seems that the band is of 4s and 3d states. Is it a bug in the routine that calculates DOS?

The calculation above are simple bandstructure and DOS calculations on 2atom diamond lattice of Ge. With Silicon the same is observed.
Exc is GGA.PBE
Density mesh cutoff is 110 Hartree
Kmesh - 18x8x18 and for DOS 25x25x25
basis set is BasisLDAPZHGH.Germanium_4_Tier_4

12

General Questions and Answers / negative DOS below the valence band

« on: May 19, 2016, 12:35 »

Strangely in Ge (or in Si) I see that the DOS projected onto p-orbitals is negative much below the valence band of Ge(or Si). What could be the reason for it?

13

General Questions and Answers / Re: Ghost atoms, relaxation, workfunction

« on: May 18, 2016, 11:37 »

Gentle Reminder.

14

General Questions and Answers / Re: Ghost atoms, relaxation, workfunction

« on: May 15, 2016, 10:19 »

Thanks Jess,
If I want to use an alternate way of modifying the basis, can you suggest me which parameter to look for?

15

General Questions and Answers / Ghost atoms, relaxation, workfunction

« on: May 13, 2016, 08:02 »

Hi,

I am getting the problems in relaxation when I include the ghost atoms. so,

How accurate the surface relaxation without ghost atoms?
And also how accurate the Workfunction calculations without ghost atoms?

Also, without ghost atoms, is it expected that with the basis set the workfunction of a metal changes significantly?