SPACI score report for 4i9n in ASTRAL 2.07:

PDB Entry: 4i9n
SPACI score: 0.34
AEROSPACI score: 0.34

Experiment type: XRAY
Resolution: 2.35
R-factor: 0.22
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.226
WCK2 WHAT_CHECK Ramachandran: -1.595
WCK3 WHAT_CHECK Chi angles: -1.929
WCK4 WHAT_CHECK Backbone: 2.672

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).