SPACI score report for 1s5i in ASTRAL 2.07:

PDB Entry: 1s5i
SPACI score: 0.29
AEROSPACI score: -1.71 (chimer; see below)

Experiment type: XRAY
Resolution: 2.7
R-factor: 0.2
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.369
WCK2 WHAT_CHECK Ramachandran: -1.987
WCK3 WHAT_CHECK Chi angles: -2.717
WCK4 WHAT_CHECK Backbone: 0.036

The AEROSPACI score for this entry is lower than the SPACI score because human-curated comments on the entry in SCOPe contain the phrase chimer. The full comment is: "MQ P18532 P01868 # natural 'chimera'; MQ P06310 P01837"

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).