Add placeholder parameters for unlisted X-H-Z hydrogen-bond triples.
Every heavy-donor / heavy-acceptor combination not present in the library
gets an inert entry (Dehb = 0 so it contributes no energy).
hbs is extended in place.
- Parameters:
p (dict) – Flat parameter dictionary, modified in place.
spec (list[str]) – Species symbols.
hbs (list[str]) – Hydrogen-bond triples, extended in place.
- Return type:
None
