SPACI score report for 1t56 in ASTRAL 1.71:

PDB Entry: 1t56
SPACI score: 0.54
AEROSPACI score: 0.54

Experiment type: XRAY
Resolution: 1.7
R-factor: 0.208
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: 0.415
WCK2 WHAT_CHECK Ramachandran: 0.68
WCK3 WHAT_CHECK Chi angles: 0.784
WCK4 WHAT_CHECK Backbone: -2.517

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).