Skip to main content

All Questions

2 votes
1 answer
134 views

Why are certain lattices compatible with only certain point groups and not all point groups?

I will limit this discussion to 2 dimensions for ease of intuition. My understanding of the 17 crystallographic plane groups is that these 17 groups represent all the possible symmetry groups of any ...
SalahTheGoat's user avatar
2 votes
0 answers
77 views

Factor Group Analysis of Na2SO4 - Site Group Symmetry

I'm still trying to understand how to construct a factor group analysis for a given molecular point group and the resulting solid state group symmetry. For this I searched for some examples and found ...
Justanotherchemist's user avatar
2 votes
1 answer
405 views

What is m.2m point group?

I'm using Bilbao Crystallographic Server to find 3D crystallographic point groups of the K points of anatase TiO2. Since the space group of anatse TiO2 is $I4_1/amd$, on this page, I found the point ...
meTchaikovsky's user avatar
1 vote
0 answers
92 views

High symmetry points and x-coordinates

Is it possible to work out the x-coordinates related to high symmetry points? The software I'm using doesn't provide me with that, so I was wondering if there is a way to manually figure it out, as I ...
Janusz's user avatar
  • 11
2 votes
2 answers
2k views

Why rutile structure have primitive unit cell instead of body centered?

In the literature (Wikipedia), I read that $\ce{MgH2}$ have a structure of rutile. Then, I looked at its space group which is $P4_2/mnm$. From this notation, I understood that it possesses a (...
Juila's user avatar
  • 37
17 votes
1 answer
521 views

Are chiral quasicrystals possible?

Quasicrystals are materials that have long-range atomic order but lack the translational symmetry of conventional crystals. All quasicrystalline tilings and packings I have read about thus far, whilst ...
Richard Terrett's user avatar