  The topological band structures of the X2YZ Heusler compounds with the
Hg2CuTi structure are investigated by using first-principles calculations
within density functional theory. Our results clearly show that a large number
of the Hg2CuTi type Heusler compounds naturally exhibit distinct band-inversion
feature, which is mainly controlled by the Y-Z zinc blende sublattice. Similar
to the half-Heusler family, the topological band order in Hg2CuTi type Heusler
compounds is sensitive to the variation of lattice constant, and most of them
possess a negative formation energy, which makes them more suitable in material
growth and could easily achieve the topological insulating behavior by alloying
or proper strain.
