SPACI score report for 12gs in ASTRAL 2.06:

PDB Entry: 12gs
SPACI score: 0.39
AEROSPACI score: 0.39

Experiment type: XRAY
Resolution: 2.1
R-factor: 0.207
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1
WCK2 WHAT_CHECK Ramachandran: -1.837
WCK3 WHAT_CHECK Chi angles: -2.111
WCK4 WHAT_CHECK Backbone: 3.274

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).