SPACI score report for 3grb in ASTRAL 2.07:

PDB Entry: 3grb
SPACI score: 0.5
AEROSPACI score: 0.5

Experiment type: XRAY
Resolution: 1.75
R-factor: 0.206
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: 0.688
WCK2 WHAT_CHECK Ramachandran: 1.233
WCK3 WHAT_CHECK Chi angles: -0.893
WCK4 WHAT_CHECK Backbone: 0.59

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).