Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - Jess Wellendorff

Pages: [1] 2 3 ... 63
1
General Questions and Answers / Re: 16 GB of memory not enough to plot a band structure from DFTB calculation!
« on: August 27, 2021, 13:18 »
Dear Alireza,

thanks for diligently reporting this issue to us. We will try to reproduce it and get back to you.

Regards,
Jess

2
General Questions and Answers / Re: How to do geometry optimization for OH molecule attached to Carbon Nanotube
« on: February 10, 2021, 15:11 »
Not clear what the problem is, please elaborate.

3
Future Releases / Re: Free VNL
« on: February 8, 2021, 11:47 »
Hi Anuja,

This is unfortunately not possible.

Regards,
Jess

4
General Questions and Answers / Re: Regarding adding remote machine
« on: February 2, 2021, 10:25 »
The page is only slightly outdated. In the Environment tab, you need to provide info on how to run QuantumATK on your cluster:
(1) which directory to run simulations in (on the cluster) ?
(2) path to atkpython on the cluster.
(3) path to mpiexec on the cluster (use the one shipped with QATK installation on the cluster).
(4) In "Export statements", provide info on which license server to use: SNPSLMD_LICENSE_FILE="[port]@[host]", exactly like required when submitting jobs manually on your cluster.

If you are in doubt about these details, I suggest you contact your IT admin.

Regards,
Jess

5
General Questions and Answers / Re: Noncollinear spin and spin orbital coupling
« on: January 28, 2021, 10:56 »
Documentation:

6
General Questions and Answers / Re: Noncollinear spin and spin orbital coupling
« on: January 28, 2021, 10:55 »
Noncollinear (NC) spin means that the spin can point in any direction in space, not just "up" and "down". So the NC spin representation is a matrix with more entries that just 2.

(1) if you do SCF with NC spin (e.g. NCGGA.PBE), the converged ground state will be in the noncollinear spin representation.
(2) Noncollinear transport just means that you allow for ground-state spins pointing in any direction what calculating the transmission spectrum.
(3) SOC requires NC representation, but you can do NC without the SOC.
(4) yes, SOC is enabled by choosing the appripriate combination of basis set and pseudopotential (I recommend SG15 for this), e.g.

Code
#----------------------------------------
# Basis Set
#----------------------------------------
basis_set = [
    BasisGGAPseudoDojoSO.Carbon_Medium,
    ]

#----------------------------------------
# Exchange-Correlation
#----------------------------------------
exchange_correlation = SOGGA.PBE

7
General Questions and Answers / Re: Export images in vector format
« on: January 28, 2021, 10:41 »
No, there is not.

8
General Questions and Answers / Re: mismatch in k-point sampling electrode to central region, error code
« on: January 28, 2021, 10:00 »
looks like error in k-point settings. Number of k-points (k_x,  k_y, k_z) must be identical in electrode calculator and device calculator.

9
General Questions and Answers / Re: DFT calculation with electric field
« on: December 3, 2020, 11:31 »
Dear Jixuan Wu,

For applying E-field in DFT optimization (or in ab initio MD) one would also use the BornEffectiveCharges (always computed from DFT) to compute the impact of E-field on DFT energy and forces. This is something we are working on, but we do not yet have a working prototype.

Regards,
Jess

10
General Questions and Answers / Re: meaning of energy cutoff value for LCAO DFT calculation
« on: November 12, 2020, 09:58 »
Perhaps the QuantumATK Manual can explain:

https://docs.quantumatk.com/manual/Types/NumericalAccuracyParameters/NumericalAccuracyParameters.html#NL.Calculators.GenericParameters.NumericalAccuracyParameters.NumericalAccuracyParameters

11
General Questions and Answers / Re: QuantumATK2019 won't open on Linux(mint) on VirtualBox
« on: November 12, 2020, 09:53 »
Hi Hadi. When you say "open it", do you mean opening the NanoLab GUI (quantumatk binary)? Did you try running atkpython from Terminal? And do you have a license server running?

12
General Questions and Answers / Re: Quantumatk is not calculating the Fermi energy
« on: October 6, 2020, 11:18 »
Don't read the Fermi level from the log files, use instead the ChemicalPotential analysis object, as done in the tutorial you mention.

13
General Questions and Answers / Re: Band Decomposed charge density of valence band and conduction band
« on: September 28, 2020, 11:06 »
Please post the question in the public forum, so that more people are available to answer.

14
General Questions and Answers / Re: IV Characteristic
« on: September 23, 2020, 11:13 »
The IV Characteristics analyzer can currently not resolve the current in spin contributions. But thank you for the suggestion.

15
General Questions and Answers / Re: Current in spin z
« on: September 23, 2020, 11:11 »
Yes, the difference between spin-up and spin-down, as it says in the Manual. https://docs.quantumatk.com/manual/includes/Spin.html

Pages: [1] 2 3 ... 63