Table 1. Summary of tetartohedrally twinned structures in the literature.

PDB code	Apparent symmetry	True symmetry	Gtwin	GNCS	R	Rfree	Twin operators†
1qzw‡	P6422	P31	222	222	0.340	0.387	i
2pi8§	P6422	P31	222	222	0.200	0.238	i
2h6r¶	P6422	P31	222	222	0.213	0.278	i
3eop††	P6422	P31	222	2	0.182	0.238	i
2y9a, 2y9b, 2y9c, 2y9d‡‡	P6122	P31	222	222	0.277	0.321	i
3nuz§§	P6522	P32	222	222	0.153	0.182	i
2pk2¶¶	I23	H3	222	222	0.272	0.306	ii
2krc†††	P21212	P1	222	222	0.200	0.240	iii

^†(i) h, k, l; −k, −h, −l; −h, −k, l; k, h −l; (ii) h, k, l; −h/3, k/3, 4l/3; h/3, −k/3, −4l/3; −2h/3, −k/3, −4l/3; (iii) h, k, l; −h, k, −l; −h, −k, l; h, −k, l.

^‡Rosendal et al. (2004 ▶).

^§Barends et al. (2005 ▶).

^¶Gayathri et al. (2007 ▶).

^††Yu et al. (2009 ▶).

^‡‡Leung et al. (2011 ▶).

^§§Joint Center for Structural Genomics, unpublished work.

^¶¶Anand et al. (2007 ▶).

^†††Roversi et al. (2011 ▶).