`center` method result in black sphere for structure with only one atom

[superstar54]

Version:

nglview: 3.0.6 ipywidgets: 7.7.4

Step to reproduce

• Create a structure with only one atom in the unit cell.
• Call center method

import nglview
from ase.build import bulk
atoms = bulk("Au")
v = nglview.show_ase(atoms)
v.add_unitcell()
v.center()
v

Note

This could be because of the overlap between the atom and the control of the viewer.