# creates: C2H4.png
from ase.build.molecule import molecule
from ase.io import write
from ase.io.pov import get_bondpairs, set_high_bondorder_pairs

C2H4 = molecule('C2H4')
r = [{'C': 0.4, 'H': 0.2}[at.symbol] for at in C2H4]
bondpairs = get_bondpairs(C2H4, radius=1.1)
high_bondorder_pairs = {}
# This defines offset, bond order, and bond_offset of the bond between 0 and 1
high_bondorder_pairs[(0, 1)] = ((0, 0, 0), 2, (0.17, 0.17, 0))
bondpairs = set_high_bondorder_pairs(bondpairs, high_bondorder_pairs)

renderer = write(
    'C2H4.pov',
    C2H4,
    format='pov',
    radii=r,
    rotation='90y',
    povray_settings=dict(canvas_width=200, bondatoms=bondpairs),
)

renderer.render()