SPACI score report for 3k23 in ASTRAL 2.06:

PDB Entry: 3k23
SPACI score: 0.22
AEROSPACI score: 0.22

Experiment type: XRAY
Resolution: 3
R-factor: 0.229
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -2.356
WCK2 WHAT_CHECK Ramachandran: -3.226
WCK3 WHAT_CHECK Chi angles: -3.14
WCK4 WHAT_CHECK Backbone: 4.244

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).