2OXK:
reference: Helix Bundle Quaternary Structure from alpha/beta-Peptide Foldamers., Horne WS, Price JL, Keck JL, Gellman SH, J Am Chem Soc. 2007 Apr 11;129(14):4178-80. Epub 2007 Mar 16. PMID: 17362016

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