SPACI score report for 2gs4 in ASTRAL 2.08:

PDB Entry: 2gs4
SPACI score: 0.48
AEROSPACI score: 0.48

Experiment type: XRAY
Resolution: 2
R-factor: 0.183
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: 0.658
WCK2 WHAT_CHECK Ramachandran: 0.878
WCK3 WHAT_CHECK Chi angles: -0.856
WCK4 WHAT_CHECK Backbone: 1.538

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).