🧪 Schottky defects occur in ionic crystals. They are pairs of point defects, where a vacancy at a cation site is matched by a vacancy at an anion site, preserving the charge balance.
Here's my two dimensional paper representation of a Schottky defect in sodium chloride. #SciArt #SciComm
Real crystals are never perfect. This is a two dimensional paper representation of a Frenkel defect. It's a pair of point defects, where an atom is displaced, leaving a vacancy and an interstitial.
🧪 #SciArt
I was getting bored of making regular convex deltahedron as paper models for chemists. Delighted with this non-convex distraction. A highly symmetry (icosahedral) 120- faced Möbius deltahedron. I'm sure mathematics is art.
🧪 #SciArt
Should be Garnet City?
Testing my net for the bicapped square antiprism. Forth time lucky! 1 missed folding an edge. 2 missed folding another edge. 3 forgot to pay attention to the sequence (made a non convex deltahedron). 4 seems okay. Maybe there's an easier net? #SciArt
I'd like to be added to the SciArt feed.
As a former scientist now more interested in art and representation.
I've converted 1 sheet of A4 cardstock into a representation of C60.
Never worked with it, but it had quite an impact on me. 1991 I saw Harry Kroto recount its discovery, and I can't overstate what a revelation this was.
A new allotrope of carbon...all my textbooks were wrong! 🧪 #SciArt #papercraft
On our way to the Cairngorm plateau at the weekend. Actually glad that I'm no longer leading the way. Parental success!
In terms of point group symmetry, I am familiar with these in terms of Schoenflies notation, the Coxeter groups is a slightly more abstract way of looking at them. Three of the deltahedra are platonic, so here the answer is yes, the others are not vertex transitive, so lower symmetries.
The second group (eg Boron hydride clusters etc) just have atoms at the vertex positions- nothing in the middle!
From my chemistry perspective, these shapes relate to two main groups of compounds. The first group have an atom in the middle, and the peripheral "coordinating" atoms are on the deltahedra vertices. The set of deltahedra have 4,5,6,7,8,9,10,and 12 vertices (coordination number in the molecule).
I've been returning to group theory over the last couple of weeks, but I need to look from the coxeter perspective before I can answer.😄
Working on some decorated deltahedra.
There are many molecular species whose shapes are represented by these interesting polyhedra. 🧪 #SciArt #MathArt #papercraft #ChemSky
It's a frosty evening in Carrbridge tonight. The bridge here is over 300 years old.
Thank you Alison. 👍😁
Changed the aspect ratio again. More spiky this time. #SciArt #mathart #papercraft
Me, homework 1985, write about "one one my idols"! Didn't have any, couldn't to do it, detention.
Today, son has the same homework.
Me: Who are you going to write about?
Son (no hesitation): Alistair McIntyre.
Huge smile on my face.
Alistair was a wonderful friend and neighbour who passed last year.
Old science: The five platonic solids (of which we think only three were known to Plato) are perfect polyhedra. They are the only 3D shapes that are; vertex-transitive, edge-transitive and face-transitive!
These 'faceless' versions are my alternative representations. 🧪 #SciArt
Same dodecahedral shape, different aspect ratios for the faces 2:1, 1 :1, 1:2.
Just messing about, could be #SciArt #mathart
What a good idea. Mine has been sat on the shelf for a few years.
Representation of melting.
🧪 #SciArt
Went a bit off-plan ( I've always been easily distracted). Accidentally made these. Was clumsily calling them open-ended prism-stellated platonic-polyhedra. Very pleased to find they are in Heinz Strobl's Snapology work.🧪
A pleasant spot, looking across the Firth of Clyde this evening.
Doesn't it just. My mother was a quilter, but I've not seen this before. Thanks.
The Gents toilet floor, University of Glasgow. Very sharp, very clean, a great example of the p4m plane group. 🧪 #symmetry #maths
The collapsible boxes are for a related unfinished project. The heptacube net looks like this...
In the new year I will turn this into a printable 2-sided pdf.
No problem.
Most of my "messing about" is me trying to figure out the best nets, and the simplest instructions, with the intention of making them freely available.
I can send you details once I've tidied up my notes, which will be next week, when I'm back in the office.
Holidays are always a good time to mess about. Been exploring dynamic paper models; this open-ended pan-symmetric hepta-cube has 3 degrees of freedom, and some of the conformations are flat!
🧪 #SciComm #Geometry
Like this?
I have to work on this paper version to get useful dihedral angle options.
