A. How well do equivalent observations agree with each other?
(a) Rmerge (Rsym) = S | Ihl - <Ih> | / S | <Ih> |
This is the traditional measure of agreement, but it increases with higher multiplicity even though the merged data is better
(b) Rmeas = Rr.i.m.= S v(n/n-1) | Ihl - <Ih> | / S | <Ih> |
The multiplicity-weight R-factor allows for the improvement in data with higher multiplicity. This is particularly useful when comparing different possible point-groups
Diederichs & Karplus, Nature Structural Biology, 4, 269-275 (1997)
Weiss & Hilgenfeld, J.Appl.Cryst. 30, 203-205 (1997)