SPACI score report for 3nns in ASTRAL 2.07:

PDB Entry: 3nns
SPACI score: 0.48
AEROSPACI score: 0.48

Experiment type: XRAY
Resolution: 1.9
R-factor: 0.189
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.275
WCK2 WHAT_CHECK Ramachandran: -0.583
WCK3 WHAT_CHECK Chi angles: -0.413
WCK4 WHAT_CHECK Backbone: 1.036

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).