bond constraints

[xiaoli1115]

Hi, by using bond constraints, the results showed no covalent bond between two specified atoms, not sure what is wrong with my codes.
Just for examples:
version: 1
sequences:

• protein:
  id: A
  sequence: AAASAAA
• ligand:
  id: D
  ccd: PNS
  constraints:
• bond:
  atom1: [A, 4, OG]
  atom2: [D, 1, P24]

I am sure the atom specifier is correct.

Thanks so much!