SPACI score report for 3r3u in ASTRAL 2.06:

PDB Entry: 3r3u
SPACI score: 0.62
AEROSPACI score: 0.62

Experiment type: XRAY
Resolution: 1.6
R-factor: 0.172
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: -1.008
WCK2 WHAT_CHECK Ramachandran: -1.292
WCK3 WHAT_CHECK Chi angles: -0.396
WCK4 WHAT_CHECK Backbone: 3.13

Note: Here are links to pages about PROCHECK and WHAT_CHECK.

Here is the full WHAT_CHECK report on this protein (linked from the WHAT_CHECK site).