SPACI score report for 3i6o in ASTRAL 2.05:

PDB Entry: 3i6o
SPACI score: 0.84
AEROSPACI score: 0.84

Experiment type: XRAY
Resolution: 1.17
R-factor: 0.161
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: 0.227
WCK2 WHAT_CHECK Ramachandran: -2.028
WCK3 WHAT_CHECK Chi angles: 0.802
WCK4 WHAT_CHECK Backbone: 2.703

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).