%load_ext autoreload
%autoreload 2

import molsysmt as msm

Get missing terminals

molecular_system = msm.convert('1BRS', to_form='molsysmt.MolSys')

aa = msm.build.get_missing_terminal_cappings(molecular_system)

aa

{412: ['OXT']}

msm.select(molecular_system, selection='atom_name=="OXT"')

[863, 1741, 2580, 3938, 4637]