  We use a combination of transmission electron microscopy, X-Ray and neutron
diffraction, SQUID magnetometry and symmetry analysis to determine the nuclear
and magnetic structure of an epitaxial LSMO film, deposited on a Si substrate.
The film undergoes a magnetic ordering transition at 260K. At 300K, in the
paramagnetic phase, the manganite film has a $I4/m$ space group. In the
magnetic phase, SQUID and neutron diffraction results lead us to assign a
ferromagnetic spin-order to the film, associated to magnetic moments with a
slightly out-of-plane component, namely $(3.5, 0, 0.3)\,\mu_B$. Symmetry
analysis further shows that only the $P\bar 1'$ group is compatible with such a
magnetic ordering.
