SPACI score report for 3i6f in ASTRAL 2.01:

PDB Entry: 3i6f
SPACI score: 0.71
AEROSPACI score: 0.71

Experiment type: XRAY
Resolution: 1.3
R-factor: 0.204
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.605
WCK2 WHAT_CHECK Ramachandran: -0.511
WCK3 WHAT_CHECK Chi angles: 0.756
WCK4 WHAT_CHECK Backbone: 0.351

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).