SPACI score report for 1pk6 in ASTRAL 2.02:

PDB Entry: 1pk6
SPACI score: 0.46
AEROSPACI score: 0.46

Experiment type: XRAY
Resolution: 1.85
R-factor: 0.201
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 2
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.203
WCK2 WHAT_CHECK Ramachandran: -1.891
WCK3 WHAT_CHECK Chi angles: -1.525
WCK4 WHAT_CHECK Backbone: -0.45

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).