SPACI score report for 2a6s in ASTRAL 1.73:

PDB Entry: 2a6s
SPACI score: 0.53
AEROSPACI score: 0.53

Experiment type: XRAY
Resolution: 1.77
R-factor: 0.195
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: 1.919
WCK2 WHAT_CHECK Ramachandran: 0.261
WCK3 WHAT_CHECK Chi angles: 1.34
WCK4 WHAT_CHECK Backbone: -8.174

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).