Beyond geometrical screening in predicting two-dimensional materials.

This perspective overviews the family of two-dimensional (2D) materials, which have attracted significant attention due to their properties and potential applications, and discusses how novel 2D materials including van der Waals (vdW) and non-vdW 2D materials have been predicted. A few thousand 2D materials have been predicted to be exfoliable or dynamically/thermodynamically stable, whereas a few hundred 2D materials have been synthesized so far, highlighting a gap between theoretical predictions and experiments. This perspective introduces recent developments in predicting the synthesizability of non-vdW 2D materials. The key lies not in stability alone, but in the 3D-2D transition.