SPACI score report for 6fab in ASTRAL 2.08:

PDB Entry: 6fab
SPACI score: 0.41
AEROSPACI score: 0.41

Experiment type: XRAY
Resolution: 1.9
R-factor: 0.209
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 3
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.639
WCK2 WHAT_CHECK Ramachandran: -0.739
WCK3 WHAT_CHECK Chi angles: -4.085
WCK4 WHAT_CHECK Backbone: -1.272

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).