SPACI score report for 1t6u in ASTRAL 1.69:

PDB Entry: 1t6u
SPACI score: 0.79
AEROSPACI score: 0.79

Experiment type: XRAY
Resolution: 1.3
R-factor: 0.158
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 1
WCK1 WHAT_CHECK Packing: 3.289
WCK2 WHAT_CHECK Ramachandran: 1.93
WCK3 WHAT_CHECK Chi angles: 2.415
WCK4 WHAT_CHECK Backbone: -1.301

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).