  In this paper we attempt to understand the different nature of first order
magnetic transformation in Mn$_3$SnC as compared to that in Mn$_3$GaC. The
transformation in Mn$_3$SnC is close to room temperature (T$_t \approx$ 280K)
and is associated with a large change in magnetic entropy that makes it a
suitable candidate for applications in ferroic cooling. Using a combination of
x-ray and neutron diffraction and x-ray absorption fine structure (XAFS)
spectroscopy we infer that the magnetic ground state consisting of
antiferromagnetic and ferromagnetic Mn atoms is due to structural distortions
present in Mn$_6$C octahedra.
