RE: "2d materials don't exist" editorial??

Yes I think that is correct. You can choose either, depending on the level of approximation you think is worth using. However, there is a nagging worry to which I do not have a certain answer. It is this. With normal 3-d crystals we are used to using group theoretical representations that are

Re: "2d materials don't exist" editorial??

Pardon me for intruding, but if a substance is only 1 atom thick, is it not the case that its symmetry is reasonably given by one of the 17 plane groups, or alternatively by the layer group which simply inserts a mirror in the plane? Robert Gould Tel. 0131 447 8513 or 0796 040 3872 On Fri, 30

RE: "2d materials don't exist" editorial??

Since everything is made of atoms all materials are 3-dimensional. The differences lie in the dimensionality of the periodicity, which can be n-dimensional. In the case of graphene, you can consider it to be 2-dimensional if you are willing to approximate atoms as having 0 thickness, and then

RE: "2d materials don't exist" editorial??

Uff, I do not know who has written this page https://en.wikipedia.org/wiki/Single-layer_materials#C:_graphene_and_graphyne [http://upload.wikimedia.org/wikipedia/commons/thumb/9/9e/Graphen.jpg/220px-Graphen.jpg1z@]

Re: "2d materials don't exist" editorial??

If you want to have a rant, just have a look at the wikipedia page for single-layer materials. Phosphorene is particularly egregious: https://en.wikipedia.org/wiki/File:Phosphorene_structure.png On Fri, 30 Dec 2022 at 20:30, Radovan Cerny wrote: > OK, I understand. Thank you Mike. > > The

RE: "2d materials don't exist" editorial??

OK, I understand. Thank you Mike. The graphene is then 2P material with the layer group p6/mmm. Can somebody give me an example of a 2D material with the plane group p6mm? Thank you Radovan Radovan Cerny Laboratoire de Cristallographie Université de Genève 24, quai Ernest-Ansermet CH-1211

Re: "2d materials don't exist" editorial??

Radovan Not quite. Graphene is a 3d material but has periodicity in 2d making its symmetry given by one of the 80 subperiodic layer groups. Mike Glazer Get Outlook for Android From: rietveld_l-requ...@ill.fr on behalf of Radovan Cerny

RE: "2d materials don't exist" editorial??

Thank you Matt, for bringing this subject which I have never taken too seriously, butt as Massimo pointed out in his paper, there are important differences in what symmetry allows for 2D and what for 2P, for example. I feel now a bit responsible, because my colleagues at the Quantum matter