Does the Z2pack can run with Quantum Espresso 6.6

Yubin Fu yubin.fu at
Tue Dec 15 23:39:45 CET 2020

Dear Dr. Gresch,

Thank you very much for developing the Z2pack. Recently I am learning to use Z2pack to investigate 1D GNRs. But I have some problems when I start the example of Bismuth by using QE6.6 with Wannier90? on HPC.

The error is: AttributeError: 'NoneType' object has no attribute 'find'. I checked it from the Internet, it seems there are many different reasons. I checked the position of 'find'. It is in this part:

# Copying the lattice parameters from into
cell = ET.parse('scf/').find('CELL').find('DIRECT_LATTICE_VECTORS')
unit = cell[0].attrib['UNITS']
lattice = '\n '.join([line.text.strip('\n ') for line in cell[1:]])

I checked the data-file.xml and found the 'cell' part but no 'DIRECT_LATTICE_VECTORS' part. So it is because of the absence of 'DIRECT_LATTICE_VECTORS' part that causes the error? Or you have better suggestions. I out the and data-file.xml file in the attachments. It will be great if you can have a check.

I also checked the example of the folder in z2pack and found that the Quantum Espresso version is 5.1.1, which is an older version compared with version 6.6. Therefore, the data-file.xml should be the data-file-schema.xml file (I just changed). Also the content of the .xml file in version 5.1.1 is quite different from version 6.6. I cannot find the keyword 'DIRECT_LATTICE_VECTORS' (you can see it in the attachment). Also I'm not sure the following unit and lattice data will be correct.

So would you mind to check the file for QE6.6? I found that I cannot do it by myself.

Thank you very much in advance.

Best regards,


Dr. Yubin Fu
Technische Universität Dresden
Faculty of Science
Department of Chemistry and Food Chemistry
Chair of Moleculare Functional Materials
Bergstraße 66
New Chemistry Building, Room 253
01069 Dresden
Phone: +49 351 463 43259
E-Mail: yubin.fu at
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