Error: Lattice matrix undefined.

[henrik-schopmans]

I am using PyXtal to generate atomic crystals of various space groups, and for most cases it works perfectly. However, for roughly 1 in 1000 crystals that I generate, I get the warning "Error: Lattice matrix undefined.". I was so far not able to find out why this happens.

Should I be worried about this? Or is this somehow handled internally? I was thinking about just skipping the structure if this error occurs and retry.

[qzhu2017]

Can you show me the exact script and output message?

[henrik-schopmans]

Here is an example (it doesn't always happen, so I just repeat the random generation 100 times):

from pyxtal import pyxtal

my_crystal = pyxtal()

for i in range(0, 100):
    my_crystal.from_random(
        dim=3, group=14, species=["He"], numIons=[4],
    )

This is the warning:

UserWarning: Error: Could not generate lattice matrix.

UserWarning: Error: Lattice matrix undefined.
  warn(text)

[qzhu2017]

@Reignbeaux
I just made some fix. Can you update the code and run the following with more examples for your application?

from pyxtal import pyxtal

for i in range(0, 100):
    my_crystal = pyxtal()
    my_crystal.from_random(3, 14, ["He"], [4])
    print(i, my_crystal.valid)

Ideally, you should use the structure only when my_crystal.valid=True

Let me know how it works.

[henrik-schopmans]

With your code, I now get the exception
unsupported operand type(s) for *: 'float' and 'NoneType'
whenever the mentioned warnings occur. my_crystal.valid is false. And again, this error only happens sometimes.

edit: Sorry, I was using the wrong environment with the old code... With your changes, it now works perfectly. Thank you very much!

[qzhu2017]

Great, I am closing this issue now...