Table 1. A list of JCSG data sets with ice-ring pathologies.

The improvement in R _free reported by REFMAC5 for data integrated using the global background-model algorithm over data integrated with the default background algorithm is given for profile-fitted intensities (prf) and summation intensities (sum). For each data set, the same set of integrated reflections were used for the different sets of processing. Here, Δ = R _default − R _global; a positive value indicates an improvement using the global background-model algorithm. For bevity, columns with data from the default background algorithm are labelled ‘D’ and columns with data from the global background algorithm are labelled ‘G’. The completeness is shown for the data processed (DIALS) and the completeness reported in the PDB. For 4puc, an R _free of 19.98% is reported in the PDB. For this data set, reflections falling on ice rings were excluded from processing, resulting in low completeness. Refining the subset of reflections present in the deposited data processed using the new background algorithm against the deposited structure resulted in an R _free of 19.46%.

				Completeness (%)		R free (sum) (%)			R free (prf) (%)
PDB code	Space group	Resolution (Å)	Multiplicity	DIALS	PDB	D	G	Δ	D	G	Δ
4dn6	P42212	2.80	12.6	100.0	99.0	35.1	34.0	1.1	34.2	33.1	1.1
4e6e	P3221	2.12	12.5	99.9	99.6	29.7	26.8	2.8	26.7	25.6	1.1
4ef1	P1211	1.90	3.4	98.0	97.8	34.7	31.9	2.8	31.7	30.2	1.5
4epz	C2221	1.68	4.2	98.5	98.0	25.1	22.6	2.5	22.2	21.4	0.8
4ezg	P212121	1.50	5.3	98.8	99.0	23.5	22.2	1.3	20.2	19.8	0.4
4fmr	P1211	2.25	6.9	97.2	97.9	26.4	25.0	1.4	25.5	24.6	1.0
4hf7	C2221	1.77	9.8	99.7	98.2	36.9	32.1	4.8	28.9	27.5	1.4
4iej	P6122	1.45	8.3	100.0	99.8	30.9	29.5	1.3	27.2	26.6	0.6
4kw2	F432	2.32	110.4	100.0	99.8	23.9	23.8	0.1	23.0	22.9	0.1
4mjg	P3221	2.65	8.2	99.9	88.7	29.7	28.3	1.4	28.3	27.6	0.7
4opm	C121	1.70	7.0	99.6	97.1	23.4	22.7	0.7	20.9	20.7	0.2
4ps6	P1211	1.25	6.2	93.7	85.8	21.5	20.3	1.2	18.4	17.9	0.5
4puc	P212121	2.00	9.2	99.3	78.1	29.8	25.4	4.4	28.1	23.2	4.9