Topics

1

General Questions and Answers / Setting max_interaction_range for phonon dispersion

« on: March 18, 2023, 15:17 »

Hi,
What general guidelines should be followed when setting "max_interaction_range" for phonon dispersion calculations to achieve reliable results, taking into account its effects on supercell size and the occurrence of imaginary frequencies? Specifically, when using the default interaction range, larger supercells are suggested 

Code

repetitions = checkNumberOfRepetitions(bulk_configuration),

while specifying a smaller max_interaction_range leads to smaller supercells 

Code

repetitions = checkNumberOfRepetitions(bulk_configuration, max_interaction_range=5.0*Angstrom).

Furthermore, the choice of interaction range can influence the presence or absence of imaginary frequencies in different cases.
For some systems, the lower interaction range manages to eliminate imaginary frequencies, while the default value of the interaction range shows imaginary frequencies, and there are some cases in which situations got reversed i.e default interaction range eliminates imaginary frequency and the lower interaction range does not.
So, is there any general rule which needs to be followed while calculating reliable phonon dispersion?

Best regard,
krabidix

                                 
 

2

General Questions and Answers / Moment Tensor Potential Attribute

« on: March 12, 2023, 18:33 »

Hi,
I was trying to run the tutorial on MTP  https://docs.quantumatk.com/tutorials/mtp_basic/mtp_basic.html.
The tutorial works fine, although to plot the results the below commands:

Code

moment_tensor_potential_training=nlread('MTP_basics_results.hdf5',MomentTensorPotentialTraining)[0]
moment_tensor_potential_training._nlplotscatter(fit_index=1)

are not working.
When using 2022.12 version following error showed up:
Traceback (most recent call last):
  File "/n/work00/software/quantumatk/2022.12/bin/../atkpython/bin/atkpython", line 8, in <module>
    sys.exit(__run_atkpython())
  File "zipdir/ATKExecutables/atkwrappers/__init__.py", line 879, in __run_atkpython
  File "plot.py", line 2, in <module>
    moment_tensor_potential_training._nlplotscatter(fit_index=1)
AttributeError: 'MomentTensorPotentialTraining' object has no attribute '_nlplotscatter'

When version 2022.03-sp1 used following error occurred:
  File "zipdir/NL/IO/NLSaveUtilities.py", line 669, in nlread
  File "zipdir/NL/IO/HDF5.py", line 568, in readHDF5
  File "zipdir/NL/IO/HDF5.py", line 699, in readHDF5Group
  File "zipdir/NL/IO/HDF5.py", line 638, in readHDF5GroupToSerializable
  File "zipdir/NL/IO/HDF5.py", line 614, in readHDF5Dict
  File "zipdir/NL/IO/HDF5.py", line 699, in readHDF5Group
  File "zipdir/NL/IO/HDF5.py", line 659, in readHDF5GroupToSerializable
  File "zipdir/NL/IO/Serializable.py", line 331, in _fromVersionedData
  File "zipdir/NL/CommonConcepts/Calculator.py", line 67, in _createObject
  File "zipdir/NL/QuantumATK/ScopeExecuter.py", line 244, in scope_execute
NL.ComputerScienceUtilities.Exceptions.NLScopeExecutionError: __init__() got an unexpected keyword argument 'paw_grid_tolerance'

Kindly, help me in resolving the problem.

3

General Questions and Answers / Data preview is not visible!

« on: January 3, 2023, 12:24 »

Hi,

In QuantumATK 2022.12 version how can we enable data preview? The data preview is not visible.

https://docs.quantumatk.com/guides/data_view/data_view.html

Thanks

4

General Questions and Answers / Unable to reproduce phonon dispersion in QuantumATK

« on: December 20, 2022, 14:44 »

Dear QuantumATK experts,

I tried to replicate the phonon band structure of a simple system (hexagonal monolayer of Cu) as done in https://doi.org/10.1155/2016/8429510 (see Fig 3 or attached image Phonon_bs_ref.PNG)
The results from QuantumATK have imaginary frequencies and even after tuning parameters (e.g: max_interaction_range, atomic_displacement) that control the force constants, I am not able to vanish the imaginary frequencies (see attached Phonon_bs_qatk.PNG).

Please, comment on how can I rid of these imaginary frequencies.


The input file is also attached.


Thanks!
krabidix