  Based on a two-orbital honeycomb lattice model and random phase
approximation, we investigate the pairing symmetry of the Ni-based
transition-metal trichalcogenide. We find that an I-wave (A2g) state and a
chiral d-wave state are dominant and nearly degenerate for typical electron and
hole dopings. These two states carry nontrivial topological properties, which
are manifested by the presence of chiral edge states in the d+id-wave state and
dispersionless Andreev bound state at zero energy in the I-wave state. Ni-based
transition-metal trichalcogenides provide us a new platform to study the exotic
phenomena emerged from electron-electron correlation effects.
