Tests:
I. C6H5Br: Bromobenzene molecule
r_ab  expt*   uspp
----   ----    ----
C-Br   1.87    1.90
C-H    1.07    1.09
C-C    1.40    1.39

* Microwave results interpreted by assuming that hexagonal symmetry of
  benzene ring is maintained.

II.  EA of Bromine (Br+e- -> Br-)
Expt. 3.364 eV
USPP. 3.409 eV *
* Energy of Br- determined by Makov-Payne-type fitting & extrapolation, 
  low symmetry (non-spherical) Br energy used in comparison.

III.  Br2 Dimer (isolated)
Bond length: USPP- 2.30 Angstroms
             Expt- 2.28 Angstroms

IV.  fcc NaBr *

Lattice Constant
---------------
Expt 11.26 Bohr / USPP 11.417 Bohr

Bulk Modulus
------------
Expt 19.47 GPa / USPP 17.62 GPa

* Na potential: Na.pbe-sp-van_ak.UPF

V.   fcc AgBr *

Lattice Constant
---------------
Expt 10.91 Bohr / 11.05 Bohr

Bulk Modulus
------------
Expt 44.03 GPa / USPP 40.18 GPa

* Ag potential: Ag.pbe-d-rrkjus.UPF