SPACI score report for 2bum in ASTRAL 2.01:

PDB Entry: 2bum
SPACI score: 0.52
AEROSPACI score: 0.52

Experiment type: XRAY
Resolution: 1.8
R-factor: 0.185
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -2
WCK2 WHAT_CHECK Ramachandran: -0.617
WCK3 WHAT_CHECK Chi angles: -0.146
WCK4 WHAT_CHECK Backbone: 2.134

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).