  Highly accurate variational calculations, based on a few-parameter,
physically adequate trial function, are carried out for the hydrogen molecule
\hh in inclined configuration, where the molecular axis forms an angle $\theta$
with respect to the direction of a uniform constant magnetic field ${\bf B}$,
for $B=0,\, 0.1,\, 0.175$ and $0.2\,$a.u. Three inclinations
$\theta=0^\circ,\,45^\circ,\,90^\circ$ are studied in detail with emphasis to
the ground state $1_g$. Diamagnetic and paramagnetic susceptibilities are
calculated (for $\theta=45^\circ$ for the first time), they are in agreement
with the experimental data and with other calculations. For $B=0,\, 0.1$ and
$0.2\,$a.u. potential energy curves $E$ vs $R$ are built for each inclination,
they are interpolated by simple, two-point Pad\'e approximant $Pade[2/6](R)$
with accuracy of not less than 4 significant digits. Spectra of rovibrational
states are calculated for the first time. It was found that the optimal
configuration of the ground state for $B \leq B_{cr}=0.178\,$a.u. corresponds
always to the parallel configuration, $\theta=0$, thus, it is a $^1\Sigma_g$
state. The state $1_g$ remains bound for any magnetic field, becoming
metastable for $B > B_{cr}$, while for $B_{cr} < B < 12$\,a.u. the ground state
corresponds to two isolated hydrogen atoms with parallel spins.
