SPACI score report for 1b4j in ASTRAL 1.55:

PDB Entry: 1b4j
SPACI score: 0.23
AEROSPACI score: 0.23 (chimer; see below)

Experiment type: XRAY
Resolution: 2.9
R-factor: 0.193
PCK1 PROCHECK Ramachandran: 2
PCK2 PROCHECK Chi-1 angle: 3
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -3.248
WCK2 WHAT_CHECK Ramachandran: -3.189
WCK3 WHAT_CHECK Chi angles: -3.058
WCK4 WHAT_CHECK Backbone: -0.709

The AEROSPACI score for this entry is lower than the SPACI score because human-curated comments on the entry in SCOP contain the phrase chimer. The full comment is: "part of a chimeric anti-gamma-interferon Fab"

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).