SPACI score report for 3a8b in ASTRAL 2.06:

PDB Entry: 3a8b
SPACI score: 0.57
AEROSPACI score: 0.57

Experiment type: XRAY
Resolution: 1.75
R-factor: 0.158
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: 3.589
WCK2 WHAT_CHECK Ramachandran: -0.349
WCK3 WHAT_CHECK Chi angles: 0.32
WCK4 WHAT_CHECK Backbone: 2.051

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).