Complex sentence: The 122 iron arsenide unconventional superconductors are part of a new class of iron-based superconductors, discovered to be superconducting in 2008, that form in the tetragonal I4/mmm, ThCr 2 Si 2 type, crystal structure.
Split into simpler sentences: The 122 iron arsenide unconventional superconductors are part of a new class of iron-based superconductors. They form in the tetragonal I4/mmm, ThCr 2 Si 2 type, crystal structure.