SPACI score report for 2xu4 in ASTRAL 2.06:

PDB Entry: 2xu4
SPACI score: 0.89
AEROSPACI score: 0.89

Experiment type: XRAY
Resolution: 1.12
R-factor: 0.14171
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -3.006
WCK2 WHAT_CHECK Ramachandran: -2.028
WCK3 WHAT_CHECK Chi angles: 0.001
WCK4 WHAT_CHECK Backbone: -1.208

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).