SPACI score report for 2nta in ASTRAL 2.03:

PDB Entry: 2nta
SPACI score: 0.41
AEROSPACI score: 0.41

Experiment type: XRAY
Resolution: 2.1
R-factor: 0.215
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.389
WCK2 WHAT_CHECK Ramachandran: -0.411
WCK3 WHAT_CHECK Chi angles: -0.155
WCK4 WHAT_CHECK Backbone: 0.786

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).