SPACI score report for 2r56 in ASTRAL 2.05:

PDB Entry: 2r56
SPACI score: 0.23
AEROSPACI score: 0.23

Experiment type: XRAY
Resolution: 2.8
R-factor: 0.246
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -0.904
WCK2 WHAT_CHECK Ramachandran: -2.988
WCK3 WHAT_CHECK Chi angles: -2.374
WCK4 WHAT_CHECK Backbone: -0.04

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).