I have some unusual crystal diffraction data I'd like to get your input on.
Almost a year ago I shot some small rods sticking out of a loop, so basically no liquid around them - using the microfocus MX2 beamline at the australian synchrotron, collected on an EIGER 16M detector.
The crystals diffracted weakly and was seemingly not viable at first glance because of high Rmerge/Rpims. See the aimless summary at the bottom of this post. This seemed to stem from a low spot intensity at low resolutions (I/sd(I)=4.6), but since the CC1/2
was fine I went with it anyway.
Here I also noted an unusually low Mosaicity, 0.05, and Wilson B-factors, 8.02 Å^2.
Low resolution limit 41.34 41.34 2.49
High resolution limit 2.40 8.98 2.40
Rmerge (within I+/I-) 0.231 0.084 0.782
Rmerge (all I+ and I-) 0.266 0.099 0.983
Rmeas (within I+/I-) 0.323 0.118 1.091
Rmeas (all I+ & I-) 0.317 0.118 1.167
Rpim (within I+/I-) 0.225 0.084 0.759
Rpim (all I+ & I-) 0.171 0.063 0.623
Rmerge in top intensity bin 0.079 - -
Total number of observations 19901 362 2067
Total number unique 6054 126 611
Mean((I)/sd(I)) 2.7 4.6 1.0
Mn(I) half-set correlation CC(1/2) 0.958 0.991 0.570
Completeness 98.6 98.2 97.3
Multiplicity 3.3 2.9 3.4
Mean(Chi^2) 0.48 0.33 0.50
Anomalous completeness 81.7 92.2 75.1
Anomalous multiplicity 1.5 1.8 1.9
DelAnom correlation between half-sets -0.003 0.041 0.045
Mid-Slope of Anom Normal Probability 0.704 - -
The anomalous signal appears to be weak so anomalous flag was left OFF
Estimates of resolution limits: overall
from half-dataset correlation CC(1/2) > 0.30: limit = 2.40A == maximum resolution
from Mn(I/sd) > 1.50: limit = 2.67A
from Mn(I/sd) > 2.00: limit = 2.87A
Estimates of resolution limits in reciprocal lattice directions:
Along 0.96 a* - 0.28 c*
from half-dataset correlation CC(1/2) > 0.30: limit = 2.40A == maximum resolution
from Mn(I/sd) > 1.50: limit = 2.40A == maximum resolution
Along k axis
from half-dataset correlation CC(1/2) > 0.30: limit = 2.40A == maximum resolution
from Mn(I/sd) > 1.50: limit = 2.86A
Along -0.17 a* + 0.99 c*
from half-dataset correlation CC(1/2) > 0.30: limit = 2.40A == maximum resolution
from Mn(I/sd) > 1.50: limit = 2.98A
Anisotropic deltaB (i.e. range of principal components), A^2: 8.62
Average unit cell: 44.93 41.90 45.83 90.00 115.57 90.00
Space group: P 1 21 1
Average mosaicity: 0.05
Minimum and maximum SD correction factors: Fulls 1.27 1.28 Partials 0.00 0.00