SPACI score report for 6zk8 in ASTRAL 2.07:

WARNING! The SPACI score for this entry is not valid. The R-factor is not available and an abitrary R-factor has been used.

PDB Entry: 6zk8
SPACI score: 0.44 (not valid)
AEROSPACI score: 0.44 (not valid)

Experiment type: XRAY
Resolution: 1.83
R-factor: 0.25
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.66
WCK2 WHAT_CHECK Ramachandran: -1.342
WCK3 WHAT_CHECK Chi angles: -0.35
WCK4 WHAT_CHECK Backbone: 2.828

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).