SPACI score report for 3zf4 in ASTRAL 2.07:

PDB Entry: 3zf4
SPACI score: 0.18
AEROSPACI score: 0.18

Experiment type: XRAY
Resolution: 3.1
R-factor: 0.24698
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 3
WCK1 WHAT_CHECK Packing: -1.926
WCK2 WHAT_CHECK Ramachandran: -1.569
WCK3 WHAT_CHECK Chi angles: -1.412
WCK4 WHAT_CHECK Backbone: 2.243

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).