Recent Posts

71

General Questions and Answers / Re: how to restart Defect MTP Training after interruption

« Last post by Anders Blom on September 3, 2025, 03:18 »

In the normal case, the MTP training scripts are fully restartable. So just run it again in the same directory and it will pick up where it left off. But there are many details, so perhaps it doesn't always work...

72

Scripts, Tutorials and Applications / Re: How to Apply Heat Flux in NEMD Simulations Using the "Exchange Interval" Option

« Last post by Anders Blom on September 3, 2025, 03:14 »

The heat sinks need to be a bit bigger than just a few atoms, usually 4-5 layers is probably fine.
The other fundamental questions should be answered in the references under https://docs.quantumatk.com/manual/Types/NonEquilibriumMomentumExchange/NonEquilibriumMomentumExchange.html

73

General Questions and Answers / Re: CALCULATED CARRIER CONCENTRATION

« Last post by Anders Blom on September 3, 2025, 03:11 »

Use density_of_states.calculateCarrierConcentration(...)

74

General Questions and Answers / Re: Analyzing spin-resolved currents across different versions of QuantumATK

« Last post by Anders Blom on September 3, 2025, 03:10 »

Frank, I missed this while on vacation. 2022 files should be fully compatible. It should be very easy to solve with a few lines of Python code, but would need a few more details, like if this is an IVCharacteristics object, or noncollinear calculations, etc. We can handle it over emails.

75

General Questions and Answers / Re: Kerker Preconditioner for LCAO DFT calculations in X-2025.06

« Last post by Anders Blom on September 3, 2025, 03:07 »

Don't use the Kerker preconditioner, I have never seen it give any benefits.

76

General Questions and Answers / Re: Non collinear Spin Relaxation

« Last post by Anders Blom on September 3, 2025, 03:05 »

Pls share input and output, else there is no way to tell if you made some simple mistake. But it is an old tutorial, so perhaps something needs updating, we can check.

77

General Questions and Answers / Re: DFT Phonon Transmission

« Last post by Anders Blom on September 3, 2025, 03:03 »

If you go to 1x1 then at least turn on the Wigner-Seitz scheme, else you are making a Gamma point phonon approximation. I would probably check if some of the machine-learned forcefields like MACE or M3GNet give at least decent phonon dispersions, and if so use them, for a much, much, much shorter calculation time, which hopefully is at least equally qualitative as a very approximate DFT simulation.

78

General Questions and Answers / Re: Issue to apply uniaxial stress on built heterostructure properly

« Last post by Anders Blom on September 3, 2025, 03:00 »

It's somewhat straightforward for a bulk crystal, but how the strain should be applied in a heterostructure is much more complex. I don't think it is enough to just change the axes A B or C, you need a more careful analysis, not least because of the lattice mismatch in the interface.

79

General Questions and Answers / Re: RAMAN Spectrum on monolayer MoS2

« Last post by Anders Blom on September 3, 2025, 02:57 »

Sorry, but it's an impossible question to answer short of myself running all calculations to check that every parameter is using correct sensible values (enough k-points, maybe needs more?), if the structure is correctly optimized (why not optimize the cell size?), etc, etc.

80

General Questions and Answers / Re: Use cases of ChargedPointDefect vs. ChargedPointDefectConfiguration

« Last post by Anders Blom on September 3, 2025, 02:55 »

Yes, that is the main difference. A new tutorial on this topic is in the works.