Recent Posts

21

General Questions and Answers / name 'TwoTemperatureModelRegion' is not defined

« Last post by Chaoning on March 11, 2026, 11:22 »

while I was running TwoTemperatureModel simulation according to  https://docs.quantumatk.com/manual/Types/TwoTemperatureModelHook/TwoTemperatureModelHook.html, an error occured, "NameError: name 'TwoTemperatureModelRegion' is not defined",  is this because my software version is too old?

22

General Questions and Answers / python.exe Fault Leading to Crash with Exception 0xc0000409

« Last post by NarTrak on March 11, 2026, 08:32 »

I used QuantumATK to simulate IV-characteristic of MoS2 transistor, but it get crash periodically without any error in log file
I have to check Event Viewer by myself and get this error:

Faulting application name: python.exe, version: 3.11.1150.1013, time stamp: 0x67922a91
Faulting module name: _NLEngine.pyd, version: 0.0.0.0, time stamp: 0x68a83e1f
Exception code: 0xc0000409
Fault offset: 0x0000000002420849
Faulting process id: 0x77A0
Faulting application start time: 0x1DCB064DB8891E5
Faulting application path: C:\PROGRA~1\QUANTU~1\QUANTU~1.06-\ATKPYT~1\python.exe
Faulting module path: c:\program files\quantumatk\quantumatk-x-2025.06-sp1\atkpython\lib\site-packages\_NLEngine.pyd
Report Id: 5eb1c13e-3327-4cda-abe7-7940c74a265f
Faulting package full name:
Faulting package-relative application ID: 

Hope to solve this issue

23

General Questions and Answers / Regarding the directionality of the gate voltage

« Last post by zwh on March 10, 2026, 09:47 »

Dear Expert,

I would like to ask for your guidance on gate voltage settings in device simulations:

1. In single-gate devices, symmetric materials show nearly identical current whether the gate is on top or bottom. However, Janus materials show large differences depending on gate position. What causes this asymmetry?

2. For dual-gate devices with symmetric top and bottom gates, how are gate voltages set in the IV Characteristics module? When sweeping from 0 V to 1 V over 11 points, does 1 V mean both gates are biased at 1 V? If so, won’t the opposing electric fields cancel each other, reducing net field strength and weakening channel control?

Your insights would be greatly appreciated.

24

General Questions and Answers / changing display format in builder

« Last post by KHipps on March 10, 2026, 03:12 »

 :'(
I accidentally hit another key (dont know which) when hitting escape key while in builder.  All the nice atom and bonds structures changed to simple stick structures.  What is worse, none of the measurement and selection tools work!
How do I get back the standard display?

25

General Questions and Answers / Mulliken population

« Last post by Jahanzaib on March 10, 2026, 00:16 »

Dear Expert,
I have a system in which a CrSn cluster is embedded on a stanene sheet. I have calculated the Mulliken spin density for the whole system. I was wondering whether it is possible to obtain the Mulliken population for only the Cr atom, or if I need to follow same approach, such as calculating the Mulliken population by adding a separate transition metal (TM) atom and then evaluating it.

Currently, I calculate the Mulliken population for the entire system using the following script:
# -------------------------------------------------------------
# Mulliken Population
# -------------------------------------------------------------
mulliken_population = MullikenPopulation(configuration)
nlsave('MP.hdf5', mulliken_population)
nlprint(mulliken_population)

26

General Questions and Answers / Re: Error in initial state energy durin electron_phonon_coupling

« Last post by kalam on March 4, 2026, 14:45 »

The initial_state_energy_range is in absolute energy unit or in respect to Fermi energy?

27

General Questions and Answers / Absorption data in Optical Spectrum Analyzer

« Last post by Nemthianhoi Zou on February 26, 2026, 12:22 »

The absorption data in the optical spectrum analyzer displays a graph of absorption (cm-1) vs wavelength (nm) upto 1722nm but the exported data of the same figure provides wavelength values from 380 to 779nm only.  Also the units in the data and the visualizer are different. I have manually converted the absoption values but the data for wavelength after 779nm is not given. Why is it so and how to fix it?

28

General Questions and Answers / Re: Geometry optimization using HSE06 DDH

« Last post by Anders Blom on February 24, 2026, 03:58 »

I believe with DDH you lose the connection between the forces and energy (i.e. zero forces are not necessarily the minimum energy), hence it's formally not available. But the discrepancies should be tiny, so just optimize the geometry with "normal" HSE and then add these more advanced options for the final computation of the electronic structure. That is, even if you could do optimization with DDH, the resulting geometry would not be significantly different.

29

General Questions and Answers / Geometry optimization using HSE06 DDH

« Last post by abhinav on February 12, 2026, 07:17 »

Why am I unable to use HSE06MetallicLocalDDH, HSE06LocalDDH, or HSE06DDH for the "OptimizeGeometry " module? It shows that OptimizeGeometry requires forces/stress, but the calculator does not allow them. Is there any other way to do that? FYI, I'm working on MXene.

30

General Questions and Answers / Showing memory error just after the 2nd IV execution task for 2x2 multi channel

« Last post by techenthusiast on February 9, 2026, 11:03 »

Good afternoon. Hope you are doing well. I am facing a memory error after the 2nd I–V execution out of 80 runs for a 2×2 multichannel FET device. Each run has 40 I–V points at constant VDS = 0.5 V. Cache memory is disabled, and the job is executed on the local disk (C/D), both having >300 GB free space.

MPI: Number of Threads =4 & Number of process =10. Just for your kind information/reference

Thank you.