SPACI score report for 3zrf in ASTRAL 2.07:

PDB Entry: 3zrf
SPACI score: 0.2
AEROSPACI score: 0.2

Experiment type: XRAY
Resolution: 2.8
R-factor: 0.22755
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 3
PCK3 PROCHECK H-bonds: 3
WCK1 WHAT_CHECK Packing: -1.898
WCK2 WHAT_CHECK Ramachandran: -4.052
WCK3 WHAT_CHECK Chi angles: -4.82
WCK4 WHAT_CHECK Backbone: 2.046

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).