SPACI score report for 1ex4 in ASTRAL 1.55:

PDB Entry: 1ex4
SPACI score: 0.21
AEROSPACI score: 0.21

Experiment type: XRAY
Resolution: 2.8
R-factor: 0.258
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.393
WCK2 WHAT_CHECK Ramachandran: -4.468
WCK3 WHAT_CHECK Chi angles: -0.885
WCK4 WHAT_CHECK Backbone: -0.818

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).