  We investigate the properties of BaNi$_2$As$_2$ using first principles
calculations. The band structure has a similar shape to that of the
BaFe$_2$As$_2$, and in particular shows a pseudogap between a manifold of six
heavy $d$ electron bands and four lighter $d$ bands, i.e. at an electron count
of six $d$ electrons per Ni. However, unlike BaFe$_2$As$_2$, where the Fermi
energy occurs at the bottom of the pseudogap, the two additional electrons per
Ni in the Ni compound place the Fermi energy in the upper manifold. Thus
BaNi$_2$As$_2$ has large Fermi surfaces very distinct from BaFe$_2$As$_2$.
Results for the phonon spectrum and electron-phonon coupling are consistent
with a classification of this material as a conventional phonon mediated
superconductor although spin fluctuations and nearness to magnetism may be
anticipated based on the value of $N(E_F)$.
