SPACI score report for 1a6g in ASTRAL 2.05:

PDB Entry: 1a6g
SPACI score: 0.91
AEROSPACI score: 0.91

Experiment type: XRAY
Resolution: 1.15
R-factor: 0.128
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: 0.185
WCK2 WHAT_CHECK Ramachandran: 1.464
WCK3 WHAT_CHECK Chi angles: 0.422
WCK4 WHAT_CHECK Backbone: 1.349

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).