SPACI score report for 3a4j in ASTRAL 2.02:

PDB Entry: 3a4j
SPACI score: 0.82
AEROSPACI score: 0.82

Experiment type: XRAY
Resolution: 1.25
R-factor: 0.129
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.274
WCK2 WHAT_CHECK Ramachandran: -1.341
WCK3 WHAT_CHECK Chi angles: 0.979
WCK4 WHAT_CHECK Backbone: -0.754

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).