Design and predict tetragonal van der Waals layered quantum materials of MPd5I2 (M=Ga, In and 3d transition metals)

Quantum materials with stacked van der Waals (vdW) layers hosting non-trivial band structure topology and magnetism have shown many interesting properties. Using high throughput density functional theory calculations, we design and predict tetragonal vdW-layered quantum materials in the MPd5I2 structure (M=Ga, In and 3d transition metals). We show that besides the known AlPd5I2, the -MPd5- structural motif of three-atomic-layer slabs separated by two I layers can accommodate a variety of metal atoms giving arise to topologically non-trivial features and highly tunable magnetic properties in both bulk and single layer 2D structures. Among them, TiPd5I2 and InPd5I2 host a pair of Dirac points and likely an additional strong topological insulator state for the band manifolds just above and below the top valence band, respectively, with their single layers hosting or near quantum spin Hall states. CrPd5I2 is a ferromagnet with a large out-of-plane magneto-anisotropy energy, desirable for rare-earth-free permanent magnets.