Recent Posts

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1
General Questions and Answers / tutorial on using COSMO-RS with version 2024 or 2025
« Last post by KHipps on June 12, 2026, 22:50 »
I am looking for information on how to use Quantum ATK with COSMO-RS to calculate temperature dependent heats of solution.  Are there tutorials anywhere?  Can anyone provide a basic example?
2
General Questions and Answers / Outliers in MACE Finetuning
« Last post by AsifShah on June 12, 2026, 02:41 »
Dear All,

I use an optimization trajectory to relax the interface between two materials, A-B, and then use it to fine-tune the MACE model.
However, there are some high-stress outliers in the optimization trajectory.
I would like to know how to delete such high-stress outlier images and save a new trajectory.


Thank you
3
Scripts, Tutorials and Applications / Seeking the tutorial for the Defect Diffusion Workflow Template
« Last post by Ada_Lee on May 26, 2026, 09:42 »
Hello everyone,
 
I am studying the manual of quantumatk's SMW and I am attempting to utilize the Defect Diffusion workflow template. May I ask if there are any tutorials on Defects and Defect Diffusion worklow template?

Best regards,
Ada
4
General Questions and Answers / LDOS from VASP ProjectOnSite
« Last post by job314 on April 28, 2026, 03:07 »
Dear all, I am still trying to visualize VASP PDOS (or LDOS). I calculate them in VASP, but when I try visualizing, I am getting the message attached, e.g "LDOS requires one of the following projections: ProjectOnSite, ProjectonShellBySite, ProjectIOnOrbitalsBySite.

I am confused - did I not specify something in VASP - I did LORBIT=11 which calculates LDOS. What is QATK asking or telling me here, how do I visualize these LDOS?

thank you

Jonas
5
General Questions and Answers / How to obtain the magnetic moment per atom in QuantumATK U-2022.12-SP1?
« Last post by q_mechanic on April 24, 2026, 20:53 »
I am using QuantumATK U-2022.12-SP1 (Windows 11). One way to obtain the magnetic moment per atom of a bulk configuration is to use, for example, the LCAO calculator with a norm conserving (NC) pseudopotential and attaching a MullikenPopulation analysis tool. I am not too versed in the physics of obtaining Mulliken populations, but in this version, this tool is not supported for a PAW pseudopotential. Unfortunately, LCAO-NC does not yield good, physical results for the material I am working with (which happens to be a collinear magnetic material, by the way), whereas LCAO-PAW does, so using MullikenPopulation is out of the question.

Searching on the QuantumATK forum, Anders Blom has suggested here that one can use a PlaneWave calculator instead (which fortunately yields the correct band structure for my material, for example), alongside with a BaderCharge analysis tool, which is available for me. However, no further description is given. Therefore, how can I obtain the magnetic moment per atom using the PlaneWave calculator (or a work-around using LCAO-PAW)?
6
General Questions and Answers / HeisenbergExchange
« Last post by PedroSousa on April 7, 2026, 13:49 »
Dear all,

I have been using the HeisenbergExchange analyzer in QuantumATK (Version X-2025.06-SP1) to calculate the magnetic exchange parameters (J_{ij}) for several materials. So far, I have followed the workflow below to extract the (J_{ij}) values:

1. Using QATK I create and run a Python script to perform the LCAO and HeisenbergExchange calculations, storing the results in an `.hdf5` file.

2. I then open `atkpython` and use the following code to extract the exchange parameters:

   ```
   he = nlread(filename, HeisenbergExchange)[0]
   d, j, n = he.uniqueCouplingMatrixElementsAndDistances()
   ```

   where `j` is a vector containing the (J_{ij}) values in meV.

This approach has worked well for several systems. However, when applying it to hexagonal Fe₃C, the resulting `j` vector contains very small values for a ferromagnetic material. The largest value obtained is approximately 1.33 meV.

On the other hand, when I open the `.hdf5` results file directly in QuantumATK, the (J_{ij}) values shown in the GUI are significantly larger and appear physically reasonable (see attached image).

I would like to understand the origin of this discrepancy and how to correctly extract the full set of (J_{ij}) values consistent with what is shown in QuantumATK.

Thank you in advance for your help.

Best regards,
Pedro Sousa
7
General Questions and Answers / Re: Define a custom dictionary for NRLTightBindingParameters
« Last post by sukhito teh on April 3, 2026, 22:42 »
Can someone help me with this problem? I am using QATKV-2023.12-SP1. I think the on-site potential used in NRLHamiltonianParametrization cannot be reproduced in SlaterKosterHamiltonianParametrization.
Thank you.
8
General Questions and Answers / Re: Finetuning MACE
« Last post by AsifShah on April 1, 2026, 03:06 »
Update:

Turns out increasing Energy/Force/Stress weight in the 2026 version causes this error, at least for my model.
Restricting weights to 30 with learning rate of 0.001 gave excellent finetuned models.


9
General Questions and Answers / Fat Band Structure
« Last post by Jahanzaib on March 27, 2026, 23:07 »
Dear Experts,
I am currently working on calculating the fat-band structure of my system and would like to analyze the electronic states around the Fermi level. In particular, I am interested in identifying which Ni (d) orbitals overlap with Sn (p) orbitals for both spin-up and spin-down channels.

I would also like to know whether it is possible to estimate the percentage contribution of each orbital character from the fat-band analysis.

For reference, I am using the following code:

# -------------------------------------------------------------

# Fat-band structure

# -------------------------------------------------------------

fat_bandstructure = FatBandstructure(
configuration=configuration,
route=['G', 'Z'],
points_per_segment=20,
bands_above_fermi_level=All,
projections=ProjectionGenerator(
atoms=ElementsProjection,
l_quantum_numbers=True,
spin=UpDownProjection,
),
)

nlsave('fat-bs.hdf5', fat_bandstructure)

I would appreciate any guidance or suggestions on how to extract and interpret this information.


10
General Questions and Answers / Re: Difference Between electrode_extension_lengths and equivalent_electrode_lengths
« Last post by Anders Blom on March 27, 2026, 19:55 »
Check the Tip in https://docs.quantumatk.com/intro/intro_tutorials/electron-transport-Si-p-n/electron-transport-Si-p-n.html and see if that answers your question
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