SPACI score report for 3a4p in ASTRAL 2.05:

PDB Entry: 3a4p
SPACI score: 0.33
AEROSPACI score: 0.33

Experiment type: XRAY
Resolution: 2.54
R-factor: 0.183
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.402
WCK2 WHAT_CHECK Ramachandran: -1.965
WCK3 WHAT_CHECK Chi angles: -3.471
WCK4 WHAT_CHECK Backbone: 3.32

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).