dispersion of FE MOX 2 monolayers show no appreciable soft mode, indicating their stability. Interestingly, we nd that the ground state of TiOF 2 monolayer is not FE (P mm2) phase rather non-polar (P mma) phase (see Supporting Information ), which is 26.620 meV/atom lower in energy than the FE phase therefore, we will not discuss its properties in the main paper.