  Intrinsic topological superconducting materials are exotic and vital to
develop the next-generation topological superconducting devices, topological
quantum calculations, and quantum information technologies. Here, we predict
the topological and nodal superconductivity of MS (M = Nb and Ta)
transition-metal sulfides by using the density functional theory for
superconductors combining with the symmetry indicators. We reveal their
higher-order topology nature with an index of Z4 = 2. These materials have a
higher Tc than the Nb or Ta metal superconductors due to their flat-band and
strong electron-phonon coupling nature. Electron doping and lighter isotopes
can effectively enhance the Tc. Our findings show that the MS (M = Nb and Ta)
systems can be new platforms to study exotic physics in the higher-order
topological superconductors, and provide a theoretical support to utilize them
as the topological superconducting devices in the field of advanced topological
quantum calculations and information technologies.
