SPACI score report for 3n68 in ASTRAL 2.07:

PDB Entry: 3n68
SPACI score: 0.32
AEROSPACI score: 0.32

Experiment type: XRAY
Resolution: 2.53
R-factor: 0.193
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.512
WCK2 WHAT_CHECK Ramachandran: -2.196
WCK3 WHAT_CHECK Chi angles: -2.571
WCK4 WHAT_CHECK Backbone: -0.287

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).