Supplementary Material

Elastic constants， Young's modulus and Poisson's ratio， spin density distribution and schematic of magnetic exchange interactions，FM, FIM and AFM energies of HHH- and HTT-phase VTiCF2 monolayers. Band structures of HHH- and HTT-phase VTiCF2 monolayers under biaxial strains without/with considering SOC effect. Energy difference between ferromagnetic state and the ferrimagnetic state and MAE of HTT-phase VTiCF2 monolayer under biaxial strains. Band structures of HHH- and HTT- VTiCF2 monolayers with different U values and HSE method. Orbital-decomposed band structures without/with SOC. Band structures of the HHH-phase VTiCF2 with magnetization along the y- and z- directions.