SPACI score report for 4pbg in ASTRAL 1.71:

PDB Entry: 4pbg
SPACI score: 0.3
AEROSPACI score: 0.3

Experiment type: XRAY
Resolution: 2.5
R-factor: 0.202
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.847
WCK2 WHAT_CHECK Ramachandran: -2.964
WCK3 WHAT_CHECK Chi angles: -1.733
WCK4 WHAT_CHECK Backbone: -6.541

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).