SPACI score report for 1b6d in ASTRAL 1.67:

PDB Entry: 1b6d
SPACI score: 0.27
AEROSPACI score: 0.27

Experiment type: XRAY
Resolution: 2.74
R-factor: 0.207
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: 1.143
WCK2 WHAT_CHECK Ramachandran: -1.271
WCK3 WHAT_CHECK Chi angles: -2.58
WCK4 WHAT_CHECK Backbone: -5.906

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).