2PPS:
reference: Photosystem I at 4 A resolution represents the first structural model of a joint photosynthetic reaction centre and core antenna system., Krauss N, Schubert WD, Klukas O, Fromme P, Witt HT, Saenger W, Nat Struct Biol 1996 Nov;3(11):965-73. PMID: 8901876

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).