workchain for spin-orbit-coupling

[qiaojunfeng]

Now the Wannier90BandsWorkChain in the opengrid branch supports spin-orbit-coupling (SOC) calculations.

Some prerequisites for using the workchain:

1. The aiida-quantumespresso should contain at least commit https://github.com/aiidateam/aiida-quantumespresso/commit/031b92b9c85ed01588de332f039af05738607375
2. I couldn't find any "standard" pseudo for SOC case (let me know if you know better pseudos), so I am just using pslibrary, as specified in this json. This json is generated by this function, essentially it downloads UPF from QE website, then you can import those UPF by verdi data upf uploadfamily. If you want to use other pseudos, just modify the json file.

How to submit the workchain: just add one line like this https://github.com/aiidateam/aiida-wannier90-workflows/blob/1decab3321fe94ed53b1f0402161c201e6ac9893/examples/workflows/run_automated_wannier.py#L187

Let me know if you have comments, suggestions!

[qiaojunfeng]

Reports from Giovanni: changing the call parameters of seekpath_structure_analysis

-from aiida_quantumespresso.workflows.functions.seekpath_structure_analysis import seekpath_structure_analysis
+from aiida_quantumespresso.calculations.functions.seekpath_structure_analysis import seekpath_structure_analysis
-            self.inputs.structure, seekpath_parameters
+            structure=self.inputs.structure, **seekpath_parameters.get_dict()

This has been done in https://github.com/aiidateam/aiida-wannier90-workflows/commit/c00dd54f9fdab8e8bca080a594d4581dfb376147 and 655c0f92280c43848dc625037f8ec0413d495a80, for master branch.

[qiaojunfeng]

Reports from Giovanni: moving the import inside the if statement:

       if self.inputs.use_opengrid:
+            from aiida_wannier90_workflows.workflows.opengrid import Wannier90OpengridWorkChain

Done in 30bd0f74afaa221d5a1c925d6f65af189be1df8e, for opengrid branch.

[qiaojunfeng]

Currently, the workchain uses pslibrary SOC pseudos, consider using the (norm-conserving) full-relativistic pseudos from the pseudo-dojo (FR v0.4, PBE, stringent)?

TODO: need cutoff table

[qiaojunfeng]

problems with the function parse_number_of_pswfc_soc:

1. with the pseudos of the pseudo-dojo, it crashes because there is no 'oc' field in the XML rows - i temporarily fixed by just removing the three lines

   oc = float(child.get('oc')) if oc < 0: continue

   but this might be wrong in general

Seems there are some slight differences between pseudos generated by different codes. I think we can skip these lines if there is no oc attribute in the PP_RELWFC tag. For all the pslibrary pseudos, all the oc are >= 0 so this if conditional has no effect. I skip the check of oc in this commit 78b65e5120020bad7608b39e335397c53f3c3401

2. I'm not sure I follow the logic num_projections += 2 * lchi if abs(jchi - lchi - 0.5) < 1e-6: num_projections += 2

For a given quantum number l, there are 2 cases:

1. j = l - 1/2 then there are 2*j + 1 = 2l states
2. j = l + 1/2 then there are 2*j + 1 = 2l + 2 states so we have to add another 2

E.g. for In pseudo

     state #   1: atom   1 (In ), wfc  1 (l=0 j=0.5 m_j=-0.5)
     state #   2: atom   1 (In ), wfc  1 (l=0 j=0.5 m_j= 0.5)
     state #   3: atom   1 (In ), wfc  2 (l=1 j=0.5 m_j=-0.5)
     state #   4: atom   1 (In ), wfc  2 (l=1 j=0.5 m_j= 0.5)
     state #   5: atom   1 (In ), wfc  3 (l=1 j=1.5 m_j=-1.5)
     state #   6: atom   1 (In ), wfc  3 (l=1 j=1.5 m_j=-0.5)
     state #   7: atom   1 (In ), wfc  3 (l=1 j=1.5 m_j= 0.5)
     state #   8: atom   1 (In ), wfc  3 (l=1 j=1.5 m_j= 1.5)
     state #   9: atom   1 (In ), wfc  4 (l=2 j=1.5 m_j=-1.5)
     state #  10: atom   1 (In ), wfc  4 (l=2 j=1.5 m_j=-0.5)
     state #  11: atom   1 (In ), wfc  4 (l=2 j=1.5 m_j= 0.5)
     state #  12: atom   1 (In ), wfc  4 (l=2 j=1.5 m_j= 1.5)
     state #  13: atom   1 (In ), wfc  5 (l=2 j=2.5 m_j=-2.5)
     state #  14: atom   1 (In ), wfc  5 (l=2 j=2.5 m_j=-1.5)
     state #  15: atom   1 (In ), wfc  5 (l=2 j=2.5 m_j=-0.5)
     state #  16: atom   1 (In ), wfc  5 (l=2 j=2.5 m_j= 0.5)
     state #  17: atom   1 (In ), wfc  5 (l=2 j=2.5 m_j= 1.5)
     state #  18: atom   1 (In ), wfc  5 (l=2 j=2.5 m_j= 2.5)

In fact this python function is a translation of the QE Fortran code uspp.f90:n_atom_wfc:

https://github.com/QEF/q-e/blob/7d5cebcf1250114756b88c6064ebe82e6f8fd835/Modules/uspp.f90#L69-L75

[giovannipizzi]

Thanks for the last clarification! It might be good to add this as a comment in the code so it's easier to understand.

[qiaojunfeng]

Thanks for the last clarification! It might be good to add this as a comment in the code so it's easier to understand.

Thanks, done in a41bd7791cd282de9d9ced7b1d1607384f770beb