SPACI score report for 3p6n in ASTRAL 2.05:

PDB Entry: 3p6n
SPACI score: 0.52
AEROSPACI score: 0.52

Experiment type: XRAY
Resolution: 1.7
R-factor: 0.205
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.961
WCK2 WHAT_CHECK Ramachandran: -1.353
WCK3 WHAT_CHECK Chi angles: -0.188
WCK4 WHAT_CHECK Backbone: -0.938

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).