SPACI score report for 1a1n in ASTRAL 2.08:

PDB Entry: 1a1n
SPACI score: 0.43
AEROSPACI score: 0.43

Experiment type: XRAY
Resolution: 2
R-factor: 0.203
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.237
WCK2 WHAT_CHECK Ramachandran: -0.048
WCK3 WHAT_CHECK Chi angles: -0.418
WCK4 WHAT_CHECK Backbone: 1.042

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).