SPACI score report for 3mu8 in ASTRAL 2.07:

PDB Entry: 3mu8
SPACI score: 0.66
AEROSPACI score: 0.66

Experiment type: XRAY
Resolution: 1.55
R-factor: 0.14
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: 2.312
WCK2 WHAT_CHECK Ramachandran: -0.253
WCK3 WHAT_CHECK Chi angles: -0.16
WCK4 WHAT_CHECK Backbone: 1.325

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).