SPACI score report for 4a6y in ASTRAL 2.05:

PDB Entry: 4a6y
SPACI score: 0.19
AEROSPACI score: 0.19

Experiment type: XRAY
Resolution: 2.9
R-factor: 0.24
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 3
WCK1 WHAT_CHECK Packing: -1.834
WCK2 WHAT_CHECK Ramachandran: -3.795
WCK3 WHAT_CHECK Chi angles: -4.543
WCK4 WHAT_CHECK Backbone: -0.947

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).