SPACI score report for 2zz6 in ASTRAL 2.06:

PDB Entry: 2zz6
SPACI score: 0.59
AEROSPACI score: 0.59

Experiment type: XRAY
Resolution: 1.66
R-factor: 0.162
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.586
WCK2 WHAT_CHECK Ramachandran: -1.336
WCK3 WHAT_CHECK Chi angles: 0.351
WCK4 WHAT_CHECK Backbone: 3.283

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).