Running the example: SpacegroupError

[din14970]

I tried to run the example but can't run the cells necessary to instantiate a Projector. I suppose it's related to issues with sginfo. I downloaded the binary available on the website (the redhat binary link) and copied it to a location on the path, but I'm getting the following error trace:

---------------------------------------------------------------------------
SpaceGroupError                           Traceback (most recent call last)
/tmp/ipykernel_46472/153190354.py in <module>
     11                                       dmin=dmin,
     12                                       dmax=dmax,
---> 13                                       thickness=thickness)

~/Documents/Programming/PythonProjects/FORKS/problematic/problematic/projector.py in from_parameters(cls, params, spgr, name, composition, **kwargs)
    208 
    209         See: xcore.unitcell.UnitCell"""
--> 210         return cls(UnitCell(params, spgr=spgr, name=name, composition=composition), **kwargs)
    211 
    212     def to_dict(self):

~/Documents/Programming/PythonProjects/FORKS/problematic/problematic/unitcell.py in __init__(self, cell_params, spgr, name, composition)
     44             self.__dict__.update(spgr.__dict__)
     45         else:
---> 46             super(UnitCell, self).__init__(spgr)
     47 
     48         self.name = name

~/Documents/Programming/PythonProjects/FORKS/problematic/problematic/spacegroup.py in __init__(self, symbol)
    506         from parse_sginfo import parse
    507 
--> 508         dct = parse(symbol)
    509 
    510         self._dct = dct

~/Documents/Programming/PythonProjects/FORKS/problematic/problematic/parse_sginfo.py in parse(spgr, verbose)
    116 
    117         if line.startswith("sginfo: Error: Unknown Space Group Symbol"):
--> 118             raise SpaceGroupError(f"No such space group '{spgr}'")
    119 
    120         if line.startswith("Reflection conditions"):

SpaceGroupError: No such space group 'Fm-3c'

Would you have any suggestions?

[stefsmeets]

Thanks for letting me know.

I immediately tried on my own pc and I get the same problem. So I did some digging and I found that the command I used to get the space group conditions is sginfo Fm-3c -Conditions. The -Conditions flag is apparently an option in the version of sginfo that I was using: https://github.com/stefsmeets/focus_package/blob/5839815c2af77fd8111a285b5e7a7f4b8a57c213/focus/src/sginfo/sginfo.c#L1810

For some reason this option is not available in the executable online (it also lacks a few other options). You could try to compile the version of focus that I used for problematic: https://github.com/stefsmeets/focus_package/tree/master/focus/src/sginfo .

[din14970]

Thanks, indeed this works oddly enough! The compiled version of the official sginfo version hosted on github does not behave the same way, in fact I find no reference to the -Condition flag in the source code.

Since this is probably the weirdest dependency requirement it might be helpful to spell out more explicitly in the README how to set this up? For others who maybe stumble on this issue: What I did is I cloned the focus_package repo, cd'd into the sginfo directory and ran make. Then I copied the created sginfo binary to the bin folder of my virtual environment (findable through echo $PATH).

Another thing that would be really helpful is if you could put some version limits on the dependencies, perhaps even just pin the versions with which you work. I ran into some importing issues and had to iteratively downgrade packages. Don't remember exactly for which versions it didn't work, sorry.

[stefsmeets]

Thanks @din14970 for the suggestions, now that I know this I will add something to the readme. Glad that it works now. And btw, I'm just as surprised as you are 😅