SPACI score report for 1a6k in ASTRAL 1.55:

PDB Entry: 1a6k
SPACI score: 0.95
AEROSPACI score: 0.95

Experiment type: XRAY
Resolution: 1.1
R-factor: 0.1323
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: 1.827
WCK2 WHAT_CHECK Ramachandran: 1.031
WCK3 WHAT_CHECK Chi angles: 1.141
WCK4 WHAT_CHECK Backbone: 1.419

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).