2N4N:
reference: Impact of Strand Number on Parallel beta-Sheet Stability., Kung VM, Cornilescu G, Gellman SH, Angew Chem Int Ed Engl. 2015 Nov 23;54(48):14336-9. doi: 10.1002/anie.201506448. , Epub 2015 Oct 12. PMID: 26457984

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