SPACI score report for 1s2o in ASTRAL 2.06:

PDB Entry: 1s2o
SPACI score: 0.68
AEROSPACI score: 0.68

Experiment type: XRAY
Resolution: 1.4
R-factor: 0.182
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.476
WCK2 WHAT_CHECK Ramachandran: -0.028
WCK3 WHAT_CHECK Chi angles: -0.064
WCK4 WHAT_CHECK Backbone: -0.279

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).