SPACI score report for 20gs in ASTRAL 1.67:

PDB Entry: 20gs
SPACI score: 0.27
AEROSPACI score: 0.27

Experiment type: XRAY
Resolution: 2.45
R-factor: 0.229
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 3
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.433
WCK2 WHAT_CHECK Ramachandran: -2.878
WCK3 WHAT_CHECK Chi angles: -2.756
WCK4 WHAT_CHECK Backbone: -5.151

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).