International
Tables for
Crystallography
Volume F
Crystallography of biological macromolecules
Edited by M. G. Rossmann and E. Arnold

International Tables for Crystallography (2006). Vol. F. ch. 16.1, p. 338   | 1 | 2 |

Table 16.1.7.1 

G. M. Sheldrick,c H. A. Hauptman,b C. M. Weeks,b* R. Millerb and I. Usóna

a Institut für Anorganisch Chemie, Universität Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany,bHauptman–Woodward Medical Research Institute, Inc., 73 High Street, Buffalo, NY 14203-1196, USA, and cLehrstuhl für Strukturchemie, Universität Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany
Correspondence e-mail:  weeks@orion.hwi.buffalo.edu

Table 16.1.7.1 | top | pdf |
Recommended parameter values for the SnB program

Values are expressed in terms of Nu, the number of unique non-H atoms (solvent atoms are typically ignored). Full-structure recommendations are for data sets measured to 1.1 Å resolution or better. Only heavy atoms or anomalous scatterers are counted for substructures.

Parameter Full structures Substructures
Phases 10Nu 30Nu
Triplet invariants 100Nu 300Nu
Peaks (with S, Cl) 0.4Nu N u
Peaks (no `heavy') 0.8Nu  
Cycles Nu/2 if [N_{u} \lt 100] or if [N_{u} \lt 400] with S, Cl etc.; Nu otherwise 2Nu (minimum 20)