SPACI score report for 3tt0 in ASTRAL 2.07:

PDB Entry: 3tt0
SPACI score: 0.28
AEROSPACI score: 0.28

Experiment type: XRAY
Resolution: 2.8
R-factor: 0.207
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.717
WCK2 WHAT_CHECK Ramachandran: 0.216
WCK3 WHAT_CHECK Chi angles: -1.229
WCK4 WHAT_CHECK Backbone: 3.276

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).