- Ξ-hyperon
- Ξ共振
- ξ函数
- Ξ超子
- ο Ceti star
- π
- π acceptor
- π-acceptor
- π-acceptor ligand
- π acid
- π-acid
- π acid ligand
- π alkene metal complexes
- π-alkene metal complexes
- π alkyne metal complexes
- π-alkyne metal complexes
- π allyl complex mechanism
- π-allyl complex mechanism
- π allylmetal complexes
- π-allylmetal complexes
- π-approximation
- π-back bonding
- π base
- π-base
- π bond