From Trivial Kondo Insulator Ce3Pt3Bi4 to Topological Nodal-Line Semimetal Ce3Pd3Bi4

Using the density functional theory combined with dynamical mean-field theory, we have performed systematic study of the electronic structure and its band topology properties of Ce3Pt3Bi4 and Ce3Pd3Bi4. At high temperatures (∼290 K), the electronic structures of both compounds resemble the open-core 4f density functional calculation results. For Ce3Pt3Bi4, clear hybridization gap can be observed below 72 K, and its coherent momentum-resolved spectral function below 18 K exhibits an topologically trivial indirect gap of ∼6 meV and resembles density functional band structure with itinerant 4f state. For Ce3Pd3Bi4, no clear hybridization gap can be observed down to 4 K, and its momentum-resolved spectral function resembles electron-doped open-core 4f density functional calculations. The band nodal points of Ce3Pd3Bi4 at 4 K are protected by the gliding-mirror symmetry and form ringlike structure. Therefore, the Ce3Pt3Bi4 compound is topologically trivial Kondo insulator while the Ce3Pd3Bi4 compound is topological nodal-line semimetal.