SPACI score report for 3c4o in ASTRAL 1.75:

PDB Entry: 3c4o
SPACI score: 0.7
AEROSPACI score: 0.7

Experiment type: XRAY
Resolution: 1.7
R-factor: 0.172
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: 0.553
WCK2 WHAT_CHECK Ramachandran: 0.646
WCK3 WHAT_CHECK Chi angles: 0.434
WCK4 WHAT_CHECK Backbone: -0.331

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).