SPACI score report for 1z6o in ASTRAL 2.08:

PDB Entry: 1z6o
SPACI score: 0.51
AEROSPACI score: 0.51

Experiment type: XRAY
Resolution: 1.91
R-factor: 0.189
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: -0.348
WCK2 WHAT_CHECK Ramachandran: 1.296
WCK3 WHAT_CHECK Chi angles: 1.238
WCK4 WHAT_CHECK Backbone: 0.474

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).