For the frustrated bilayers in this work to be stacked, one 2D layer, layer A, must be pre-stretched by a biaxial strain of a% and then stacked on the pre-compressed second 2D layer, layer B, which is compressed by a biaxial strain of b% (noting that b = -a). Lateral compression of a 2D material (layer B) might lead to buckling, and hence a more suitable scheme would be to stack the pre-stretched layer (layer A) on an unstrained layer B, such as layer A is pre-stretched by a biaxial strain of a + |b|%. This setup assumes that layer A can actually be stretched by a + |b|%, which amounts to ∼10%