Messages

1

General Questions and Answers / Inelastic current of a molecular junction

« on: May 21, 2024, 13:41 »

Dear All,

I tried to calculate the inelastic current of a molecular junction. However,  the current curve is peculiar. It goes negative and forms a peak before it goes up again. Does anyone have any idea on this negative peak? Would it be a calculation error?

My calculation procedure:
After normal DFT routine, the dynamical matrix is calculated at 0 bias. Due to the lack of computational resources, the dynamical matrix is calculated at gamma point and reused at finite bias calculations. Then I obtain the inelastic current with LOE methods.

Please find attached the I(V) and my inputs.

Thank you for your help.

Best regards,
Ml1019

2

General Questions and Answers / Re: The difference between IETS and the second derivative of A

« on: November 14, 2023, 00:58 »

See https://docs.quantumatk.com/tutorials/inelastic_electron_spectrometry_au_h2_au/inelastic_electron_spectrometry_au_h2_au.html#introduction for the difference between the two in terms of how the GUI analyzer shows it. That is, IETS=(d2I/d2V) / (dI/dV).

The two versions where you divide with dI/dV or not do however seem to vary a bit in the literature and the term IETS can be used for both.

The method inelasticElectronTunnelingSpectroscopy() returns d2I/d2V as the manual states https://docs.quantumatk.com/manual/Types/InelasticTransmissionSpectrum/InelasticTransmissionSpectrum.html.

Dear Anders,

Thank you for your explanation.

Best regards,
ml1019

3

General Questions and Answers / The difference between IETS and the second derivative of A

« on: November 7, 2023, 19:06 »

Dear All,

Can I know the difference between IETS and the second derivative of A?

Why are the intensity of the peaks in the attached two figures different?

Thank you for your help.

4

General Questions and Answers / Re: Reading HDF5 files obtained from another computer/clusters

« on: June 29, 2023, 23:18 »

Thank you for your update!

Yes, the bug is planned to be addressed in the upcoming V-2023.09 release. The HDF5 re-saving trick will still work, it's just that your file contains study objects, which cannot be nlsave-ed (this is something we also plan to fix soon). You can easily work around it by excluding whichever class is causing the problem, i.e. change the line before "pass" to

if x.cls in [DeviceConfiguration, <add offending class here>]:

My guess is that you have an IVCharacteristics in there, so make it

if x.cls in [DeviceConfiguration, IVCharacteristics]:

5

General Questions and Answers / Re: Reading HDF5 files obtained from another computer/clusters

« on: June 17, 2023, 14:06 »

And your aforementioned solution didn't work on the new version.

Please find below the  error.

+
Traceback (most recent call last):
  File "hdf5.py", line 10, in <module>
    nlsave(new_file, data)
  File "zipdir/NL/IO/NLSaveUtilities.py", line 474, in nlsave
  File "zipdir/NL/IO/HDF5.py", line 850, in writeHDF5Group
  File "zipdir/NL/IO/HDF5.py", line 932, in writeHDF5Group
  File "zipdir/NL/IO/HDF5.py", line 976, in writeHDF5Dict
  File "zipdir/NL/IO/HDF5.py", line 865, in writeHDF5Group
  File "zipdir/NL/Study/Study.py", line 163, in _toHDF5Group
NL.ComputerScienceUtilities.Exceptions.NLIOError: Study objects cannot be saved manually; continuous saving on disk is managed by the object directly.

Dear Anders,
For your information, I have obtained the version of 2022.12 and this bug still exists. If there is anything you need to check the bug or fix it, please do not hesitate to contact me. Thank you.

Best regards,

Well, that *should* not be needed, but I guess due to this bug, then currently yes. Or, you could just not store them at all (NoStorage), which of course lowers performance.

Could you get access to a new version and try that? We don't fix bugs in old versions anyway, and maybe it actually has been fixed; I was able to save a DeviceConfiguration in the latest version with a StoreOnDisk that used a non-existent directory, and read it back, although it was not a converged calculation.

As a workaround, which I think will work, my first suggestion is to re-save the quantities you want to analyze in the GUI into a separate new HDF5 file, except for the geometry. You could always easily add that, using your original script. You are anyway not going to perform any post-processing calculations on the laptop! (Btw, if the laptop also is Linux, you could also simply create the directory /var/tmp/pbs.6846470.pbs - the error is because that directory doesn't exist, but NanoLab is not trying to read any data from it.)

So, if your laptop is Windows, then try this on the HPC machine:

Code: python

from NL.IO.NLSaveUtilities import nlinspect
current_file = "current.hdf5"
new_file = "new.hdf5"
file_contents = nlinspect(current_file)
for x in file_contents:
    if x.cls == DeviceConfiguration:
        pass
    else:
        data = nlread(current_file, object_id=x.object_id)[0]
        nlsave(new_file, data)

The new file should be possible to open on the laptop, I hope! You could also (still on the HPC machine) make a copy of your original script, and before the calculator is attached, add

Code: python

nlsave("new.hdf5", device_configuration)

and then stop execution of the script when it starts the calculation (or insert a bogus statement like "ffffff" right after this nlsave line). That way, the new.hdf5 file will have the geometry in it, albeit with a different fingerprint than the analysis data. We could fix that with a few more lines of code, if needed; let me know if you have problems in the further analysis.

6

General Questions and Answers / Re: Reading HDF5 files obtained from another computer/clusters

« on: June 17, 2023, 14:03 »

Dear Anders,
For your information, I have obtained the version of 2022.12 and this bug still exists. If there is anything you need to check the bug or fix it, please do not hesitate to contact me. Thank you.

Best regards,

Well, that *should* not be needed, but I guess due to this bug, then currently yes. Or, you could just not store them at all (NoStorage), which of course lowers performance.

Could you get access to a new version and try that? We don't fix bugs in old versions anyway, and maybe it actually has been fixed; I was able to save a DeviceConfiguration in the latest version with a StoreOnDisk that used a non-existent directory, and read it back, although it was not a converged calculation.

As a workaround, which I think will work, my first suggestion is to re-save the quantities you want to analyze in the GUI into a separate new HDF5 file, except for the geometry. You could always easily add that, using your original script. You are anyway not going to perform any post-processing calculations on the laptop! (Btw, if the laptop also is Linux, you could also simply create the directory /var/tmp/pbs.6846470.pbs - the error is because that directory doesn't exist, but NanoLab is not trying to read any data from it.)

So, if your laptop is Windows, then try this on the HPC machine:

Code: python

from NL.IO.NLSaveUtilities import nlinspect
current_file = "current.hdf5"
new_file = "new.hdf5"
file_contents = nlinspect(current_file)
for x in file_contents:
    if x.cls == DeviceConfiguration:
        pass
    else:
        data = nlread(current_file, object_id=x.object_id)[0]
        nlsave(new_file, data)

The new file should be possible to open on the laptop, I hope! You could also (still on the HPC machine) make a copy of your original script, and before the calculator is attached, add

Code: python

nlsave("new.hdf5", device_configuration)

and then stop execution of the script when it starts the calculation (or insert a bogus statement like "ffffff" right after this nlsave line). That way, the new.hdf5 file will have the geometry in it, albeit with a different fingerprint than the analysis data. We could fix that with a few more lines of code, if needed; let me know if you have problems in the further analysis.

7

General Questions and Answers / How to reduce the resources to calculate the dynamical matrix

« on: June 14, 2023, 17:21 »

Dear All,

 I tried to get the inelastic spectrum of a molecule junction but I found the resources it required are really demanding. Could you give me some suggestions to reduce the resources?
Currently I am using 128 cores with 920 gb memory.
Thank you for your help.

Please find attached the input.

Best regards

8

General Questions and Answers / Re: Reading HDF5 files obtained from another computer/clusters

« on: March 18, 2023, 02:52 »

Well, that *should* not be needed, but I guess due to this bug, then currently yes. Or, you could just not store them at all (NoStorage), which of course lowers performance.

Could you get access to a new version and try that? We don't fix bugs in old versions anyway, and maybe it actually has been fixed; I was able to save a DeviceConfiguration in the latest version with a StoreOnDisk that used a non-existent directory, and read it back, although it was not a converged calculation.

As a workaround, which I think will work, my first suggestion is to re-save the quantities you want to analyze in the GUI into a separate new HDF5 file, except for the geometry. You could always easily add that, using your original script. You are anyway not going to perform any post-processing calculations on the laptop! (Btw, if the laptop also is Linux, you could also simply create the directory /var/tmp/pbs.6846470.pbs - the error is because that directory doesn't exist, but NanoLab is not trying to read any data from it.)

So, if your laptop is Windows, then try this on the HPC machine:

Code: python

from NL.IO.NLSaveUtilities import nlinspect
current_file = "current.hdf5"
new_file = "new.hdf5"
file_contents = nlinspect(current_file)
for x in file_contents:
    if x.cls == DeviceConfiguration:
        pass
    else:
        data = nlread(current_file, object_id=x.object_id)[0]
        nlsave(new_file, data)

The new file should be possible to open on the laptop, I hope! You could also (still on the HPC machine) make a copy of your original script, and before the calculator is attached, add

Code: python

nlsave("new.hdf5", device_configuration)

and then stop execution of the script when it starts the calculation (or insert a bogus statement like "ffffff" right after this nlsave line). That way, the new.hdf5 file will have the geometry in it, albeit with a different fingerprint than the analysis data. We could fix that with a few more lines of code, if needed; let me know if you have problems in the further analysis.

Dear Anders,

Thank you for your solution! I can analyse the new hdf5 file now.

9

General Questions and Answers / Re: Reading HDF5 files obtained from another computer/clusters

« on: March 3, 2023, 13:45 »

The only case I can guess where this might occur is if you have requested the self energies to be stored on disk. Can you confirm if that is the case? If so, it seems like a "logical bug" but still something we might need to look into; if not, pls attached your input file (actually, if you can, pls do that anyway).

Also pls confirm which version of the code us used.

Dear Anders,

Thank you for your reply. 

Yes, exactly. The self energies were stored on disk. The version I used is 2021.06-SP2.

Do you mean if I need to analyze the hdf5 file, I need to save it in memory, which obviously requires a lot more memory than before?

10

General Questions and Answers / Reading HDF5 files obtained from another computer/clusters

« on: February 18, 2023, 23:30 »

Dear all,

I obtained a hdf5 file from a calculation that ran on a hpc cluster and tried to analyse it using the GUI on my laptop. But the problem is that the working directory of hdf5 is a temporary directory and cannot be found on my own laptop. Please find below the error.

Traceback (most recent call last):
  File "test.py", line 6, in <module>
Traceback (most recent call last):
  File "test.py", line 6, in <module>
    configuration = nlread(path, object_id='DeviceConfiguration_0')[0]
  File "zipdir/NL/IO/NLSaveUtilities.py", line 898, in nlread
  File "zipdir/NL/IO/HDF5.py", line 558, in readHDF5
  File "zipdir/NL/IO/HDF5.py", line 639, in readHDF5Group
  File "zipdir/NL/IO/HDF5.py", line 600, in readHDF5Dict
  File "zipdir/NL/IO/HDF5.py", line 660, in readHDF5Group
  File "zipdir/NL/IO/Serializable.py", line 331, in _fromVersionedData
  File "zipdir/NL/CommonConcepts/Calculator.py", line 67, in _createObject
    configuration = nlread(path, object_id='DeviceConfiguration_0')[0]
  File "zipdir/NL/IO/NLSaveUtilities.py", line 898, in nlread
  File "zipdir/NL/QuantumATK/ScopeExecuter.py", line 244, in scope_execute
  File "zipdir/NL/IO/HDF5.py", line 558, in readHDF5
NL.ComputerScienceUtilities.Exceptions.NLScopeExecutionError: The parameter 'working_directory' must be a string to an existing directory.
The directory /var/tmp/pbs.6846470.pbs was not found.
  File "zipdir/NL/IO/HDF5.py", line 639, in readHDF5Group
  File "zipdir/NL/IO/HDF5.py", line 600, in readHDF5Dict
  File "zipdir/NL/IO/HDF5.py", line 660, in readHDF5Group
  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: The parameter 'working_directory' must be a string to an existing directory.
The directory /var/tmp/pbs.6846470.pbs was not found.

I appreciate it if you have any suggestions. Thank you