SPACI score report for 3sn5 in ASTRAL 2.03:

PDB Entry: 3sn5
SPACI score: 0.32
AEROSPACI score: 0.32

Experiment type: XRAY
Resolution: 2.75
R-factor: 0.184
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.913
WCK2 WHAT_CHECK Ramachandran: -1.888
WCK3 WHAT_CHECK Chi angles: -1.547
WCK4 WHAT_CHECK Backbone: 3.703

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).