SPACI score report for 2b4k in ASTRAL 2.08:

PDB Entry: 2b4k
SPACI score: 0.13
AEROSPACI score: 0.13

Experiment type: XRAY
Resolution: 3.3
R-factor: 0.259
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 3
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.688
WCK2 WHAT_CHECK Ramachandran: -3.303
WCK3 WHAT_CHECK Chi angles: -4.126
WCK4 WHAT_CHECK Backbone: -1.189

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).