SPACI score report for 2f6k in ASTRAL 2.05:

PDB Entry: 2f6k
SPACI score: 0.35
AEROSPACI score: 0.35

Experiment type: XRAY
Resolution: 2.5
R-factor: 0.192
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.482
WCK2 WHAT_CHECK Ramachandran: -2.041
WCK3 WHAT_CHECK Chi angles: -0.372
WCK4 WHAT_CHECK Backbone: 1.976

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).