  Intensive and extensive searches for superconductivity in materials
iso-structural, iso-electronic and iso-valent with magnesium diboride, MgB2,
have not produced superconductors with Tc close to 39K. Recently, we proposed
lithium magnesium nitride, LiMgN, as a potential MgB2-like superconductor,
based on symmetry considerations of averages of electronegativity, valence
electrons, atomic number and formula weight. Our studies show that there are
other materials that meet the same symmetry considerations like LiMgN. Here we
propose that magnesium beryllium carbide, MgBeC, one of such materials, should
be a superconductor like MgB2, with Tc near 39K.
