SPACI score report for 4epx in ASTRAL 2.06:

PDB Entry: 4epx
SPACI score: 0.56
AEROSPACI score: 0.56

Experiment type: XRAY
Resolution: 1.76
R-factor: 0.154
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.195
WCK2 WHAT_CHECK Ramachandran: -1.186
WCK3 WHAT_CHECK Chi angles: -0.489
WCK4 WHAT_CHECK Backbone: 4.569

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).