Error while generating the supercell k-path

[Gargee-123]

Hi,

I am trying to do band unfolding of BiSe-NbSe2 misfit structure on NbSe2 hexagonal unit cell. I am using VASP for my calculation. I have already generated the CHGCAR file for the misfit structure (BiSe-NbSe2). I have also done the optimization and band structure calculation NbSe2 primitive cell.

I am getting error while generating the effective band path (supercell band path) for band structure calculation and I got error as:

> ===========================================================================
> 
>                Pre-processing utility "get_SCKPTS_pre_BandUP"
>    >>> Getting the SC-KPTS you'll need for your plane-wave calc. <<<
> 
> 
>  Checking if you are working with the smallest possible SC:
>      * Your SC seems to be a perfect repetition of a smaller PC!
>        > That's OK if you really want it, but using the smallest
>          possible SC will certainly save you some time!
>      * We attempted to find a possible PC associated with it.
>        Please take a look at the file "BandUP_suggestion_of_smaller_SC_based_on_your_input_SC.POSCAR".
> 
>  Checking if working with the smallest possible ref. unit cell:
>      * OK!
>  
>  
> ===========================================================================
>                                      ERROR!!                                                                                                                                                                                                                    
> ===========================================================================
>   The SC and the reference PC that you have chosen are not commensurate!  
>   The choice of the reference PC vectors is very important and can change 
>   a lot the results of unfolding. It is particularly important to always  
>   verify that the SC and the reference PC are commensurate. Otherwise, the
>   calculated spectral weigths will most likely be very small, which will  
>   certainly cause the values of the unfolded delta_Ns to be also small.   
> ===========================================================================
> 
>  
> Traceback (most recent call last):
>   File "/home/au658188/Downloads/bandup-master/bandup", line 73, in <module>
>     run_requested_task(args)
>   File "/home/au658188/Downloads/bandup-master/src/python_interface/bandupy/runners.py", line 73, in run_requested_task
>     run_pre_bandup_tool(args)
>   File "/home/au658188/Downloads/bandup-master/src/python_interface/bandupy/runners.py", line 53, in run_pre_bandup_tool
>     for line in iter(bandup_pre_unf_run.stdout.readline, ''):
>   File "/home/au658188/anaconda3/lib/python3.8/codecs.py", line 322, in decode
>     (result, consumed) = self._buffer_decode(data, self.errors, final)
> UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa0 in position 628: invalid start byte

I am attaching the inputs I have used to generate the SC K-path. Moreover, the suggested POSCAR (supercell) file also seems very different than the one gave as input. Unfold_on_NbSe2.zip

Please help me to solve this error.

[stepan-tsirkin]

Hi @Gargee-123 ,

following comments under #21 , could you try setting "export LANG=en_US.UTF-8 and export LC_ALL=en_US.UTF-8 in your shell. Would it solve the problem?

[Gargee-123]

Hi Stepan,

I have added "export LANG=en_US.UTF-8 and export LC_ALL=en_US.UTF-8 to my .bashrc and run the BandUP code for generating the SC K-path. I am still getting the error.

===========================================================================

           Pre-processing utility "get_SCKPTS_pre_BandUP"

Getting the SC-KPTS you'll need for your plane-wave calc. <<<

Checking if you are working with the smallest possible SC:

• Your SC seems to be a perfect repetition of a smaller PC!

  That's OK if you really want it, but using the smallest possible SC will certainly save you some time!

• We attempted to find a possible PC associated with it. Please take a look at the file "BandUP_suggestion_of_smaller_SC_based_on_your_input_SC.POSCAR".

  Checking if working with the smallest possible ref. unit cell:

• OK!

=========================================================================== ERROR!!

The SC and the reference PC that you have chosen are not commensurate!
The choice of the reference PC vectors is very important and can change a lot the results of unfolding. It is particularly important to always
verify that the SC and the reference PC are commensurate. Otherwise, the Traceback (most recent call last): File "/home/au658188/Downloads/bandup-master/bandup", line 73, in run_requested_task(args) File "/home/au658188/Downloads/bandup-master/src/python_interface/bandupy/runners.py", line 73, in run_requested_task run_pre_bandup_tool(args) File "/home/au658188/Downloads/bandup-master/src/python_interface/bandupy/runners.py", line 53, in run_pre_bandup_tool for line in iter(bandup_pre_unf_run.stdout.readline, ''): File "/home/au658188/anaconda3/lib/python3.8/codecs.py", line 322, in decode (result, consumed) = self._buffer_decode(data, self.errors, final) UnicodeDecodeError: 'utf-8' codec can't decode byte 0xf0 in position 857: invalid continuation byte

[stepan-tsirkin]

Problem is the same as #27