The discovery of the ideal topological semimetallic state in experimentally accessible materials is of both fundamental and technological interest. Here, based on first-principles calculations using the virtual crystal approximation method, we study the evolution of band structures in the ${\mathrm{Ni}}_3\mathrm{In}$ cubic structure by intercalating the doped C or N atoms, termed as ${\mathrm{Ni}}_3{\mathrm{InC}}_x{\mathrm{N}}_{\left(1\text{–}x\right)}$. Through controlling the ratio of intercalated atoms, we calculate electronic structures of a series of doped samples. A distinctive feature of a nodal line occurring at the Fermi level is present at $x=0.26$, and the charge analysis indicates that the bond interaction between intercalated atoms and nickel atoms induces charge redistribution, giving rise to the rigidlike shift of bands. Within the spin-orbital coupling, the nodal line is gapped and thereby ${\mathrm{Ni}}_3{\mathrm{InC}}_x{\mathrm{N}}_{\left(1\text{–}x\right)}$ transforms into topological insulators due to the spin-rotation symmetry breaking. Moreover, the nontrivial state is insensitive to the external strain and pressure, so one can expect exotic correlation physics of massless nodal-line fermions in the doped systems of ${\mathrm{Ni}}_3{\mathrm{InC}}_x{\mathrm{N}}_{\left(1\text{–}x\right)}$. Our work provides a promising avenue to explore ideal topological massless quasiparticles in doped systems.

• Received 28 August 2023
• Revised 11 January 2024
• Accepted 3 April 2024

DOI:https://doi.org/10.1103/PhysRevB.109.205103