Table 1. Second moments of intensity (〈E ⁴〉/〈E ²〉²) in the presence and absence of twinning.

	Before anisotropy correction			Before tNCS correction		After tNCS correction
PDB code	Centric	Acentric	ΔB aniso (Å2)	Centric	Acentric	Centric	Acentric	Twin fraction	p-value
2fuq	5.04	3.10	29.0	4.42	2.81	3.01	2.01	—†	1
1un7	4.33	2.84	4.5	4.44	2.88	2.73	1.97	—†	0.221
1y9r	—	1.88	0.2	—	1.88	—	1.75	0.08	1.4 × 10−20
1eh4	2.45	2.35	0.0	2.45	2.38	2.56	1.81	0.10	3.6 × 10−6
1upp	3.05	1.84	2.3	3.04	1.84	2.52	1.71	0.46	2.1 × 10−76

^†No merohedral or pseudomerohedral twin operator possible.