SPACI score report for 3r99 in ASTRAL 2.04:

WARNING! The SPACI score for this entry is not valid. This is not an X-ray structure, so the resolution and R-factor listed may be arbitrary and not valid.

PDB Entry: 3r99
SPACI score: 0.35 (not valid)
AEROSPACI score: 0.35 (not valid)

Experiment type: NEUT+
Resolution: 2.4
R-factor: 0.211
PCK1 PROCHECK Ramachandran: 1
PCK2 PROCHECK Chi-1 angle: 1
PCK3 PROCHECK H-bonds: 2
WCK1 WHAT_CHECK Packing: -1.358
WCK2 WHAT_CHECK Ramachandran: -1.309
WCK3 WHAT_CHECK Chi angles: -0.388
WCK4 WHAT_CHECK Backbone: 0.473

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).