SPACI score report for 4nul in ASTRAL 2.08:

PDB Entry: 4nul
SPACI score: 0.5
AEROSPACI score: 0.5

Experiment type: XRAY
Resolution: 1.9
R-factor: 0.167
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.572
WCK2 WHAT_CHECK Ramachandran: 0.588
WCK3 WHAT_CHECK Chi angles: -0.173
WCK4 WHAT_CHECK Backbone: -0.644

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).