SPACI score report for 1so6 in ASTRAL 2.07:

PDB Entry: 1so6
SPACI score: 0.52
AEROSPACI score: 0.52

Experiment type: XRAY
Resolution: 1.9
R-factor: 0.16
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: -1.003
WCK2 WHAT_CHECK Ramachandran: -0.89
WCK3 WHAT_CHECK Chi angles: -1.126
WCK4 WHAT_CHECK Backbone: -0.204

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).