تغريدة مثبتة
The great migration begins? Hope to see you all there:
@jonwright76@qoto.org
English
jonathan wright
746 posts
jonathan wright
@jonwright76
Scientist in Grenoble, @[email protected]
Grenoble, France انضم Şubat 2012
782 يتبع358 المتابعون
@MacchiPiero @Robert_Palgrave @esvenssongrape @CakBakti @MikeGlazer1 Yes, and the agreement between theory and experiments is often magical.
English
@jonwright76 @Robert_Palgrave @esvenssongrape @CakBakti @MikeGlazer1 Anyway you agree that eigenmodes are also matematical constructions, right?
English
Sorry but you are wrong. Two confusions:
1. Between “lattice” and “structure”. I advise reading
iucr.org/news/newslette…
2. Between “super” and “sub”. See
iucr.org/news/newslette…
Almost everyone makes this mistake but it has consequences if trying to study symmetry properties.
Subakti Subakti@CakBakti
@MikeGlazer1 It is correctly said as "superlattices", while "superstructures" refer to crystallographic term when normal structural symmetry can no longer describe your atomic arrangements. For example, anion off-stoichiometry in perovskites system can bring your crystal symmetry lower.
English
@MikeGlazer1 Based on the responses you are getting here, we would benefit from an update to the definition of "lattice" so that it properly describes common usage.
That is going to be difficult to write!
English
It is interesting that whenever I post about the misuse of the terminology “lattice” and “structure” by chemists/physicists etc when talking about crystal structures, there is always a lot of follow-up discussion, some of it misinformed or revealing a misunderstanding.
English
@MacchiPiero @Robert_Palgrave @esvenssongrape @CakBakti @MikeGlazer1 Piero, when you wrote: "which means the electron density averaged over all possible vibrational eigenmodes of the lattice"
What is vibrating? You meant the physical crystal lattice, right?
English
@Robert_Palgrave @jonwright76 @esvenssongrape @CakBakti @MikeGlazer1 I do not understand what is the ‘physical lattice’. Lattice is a mathematical entity. It may be that a given disposition of atoms biunivocally coincides with a lattice: atoms of one type only and cirrelated by translations. This happens only in some (not all) elemental solids
English
@MacchiPiero @Robert_Palgrave @esvenssongrape @CakBakti @MikeGlazer1 In the context below, I thought @MikeGlazer1 refers to a physical sublattice. How could the mathematical one be polarised?
English
@Robert_Palgrave @jonwright76 @esvenssongrape @CakBakti @MikeGlazer1 Sub and super lattices are exactly the terms that kill the ‘physical lattice’ as you call. In order to exist, a sub or super lattice need an abstract entity like the lattice! Otherwise it is sub or supra what?
English
@MikeGlazer1 @Robert_Palgrave @MacchiPiero @esvenssongrape @CakBakti What is a lattice mode @MikeGlazer1?
English
@Robert_Palgrave @MacchiPiero @jonwright76 @esvenssongrape @CakBakti Just read a moment ago in Physics Today “moire pattern forms a periodic triangular superlattice on top of the original graphene lattice” But all lattices are periodic, no such thing as a triangular lattice and the so- called superlattice is a sublattice.
English
@Robert_Palgrave @esvenssongrape @CakBakti @MikeGlazer1 It's a descriptive vs proscriptive view of language (doi.org/10.1002/978111…). "Lattice" is understood by native English speakers in the broader descriptive sense.
English
@esvenssongrape @CakBakti @MikeGlazer1 Two meanings of lattice are common in the literature.
Arguments can be made that either is the 'correct' one, but assertions like that are unlikely to actually bring any consensus.
English
jonathan wright أُعيد تغريده
Hello everyone,
We have multiple postdoc and PhD positions available in the area of advanced nuclear fuels. Please see the following links for more details. If you know anyone who might be interested, please let them know.
PDF-1: imechanica.org/node/27200
imechanica.org/node/27202
English
jonathan wright أُعيد تغريده
Your code could be nicer. You could have adopted better conventions. There is probably a lot of code that you don't need.
However, your users only care about what your code can do, whether it can do it correctly and whether it can do it efficiently.
Focus on these three: features, correctness and efficiency.
The rest is shallow and vain.
Richard Startin@richardstartin
Things I will not say on my death bed: I wish I’d spent more time refactoring
English
@xtalb 10% is published garbage? It sounds like it needs a systematic review!
English
Frightening. Searching for "Rietveld refinement" in Google Scholar for 2024 gives already >1300 entries. Among the first 30 in the list, 3 show image manipulations (10%). Here is the third : #1" target="_blank" rel="nofollow noopener">pubpeer.com/publications/D…
English
jonathan wright أُعيد تغريده
jonathan wright أُعيد تغريده
Woah getting a bit crazy now. Look at all those peaks not fitted at all 🤯
English
jonathan wright أُعيد تغريده
English
@jonwright76 @Robert_Palgrave Everybody knows it’s actually the University of Northampton, just with a very long, university-wide sabbatical (with reincarnated returns).
English
I have never read a sentence which better illustrates Durham University.
English
QME
jonathan wright أُعيد تغريده
Pleased to have Prof Paul Attfield for today’s @aberdeenuni chem dept seminar presenting his work as winner of the John Goodenough Award @RoySocChem "New Materials from High Pressure" 💎💫
First time I saw my academic parent and grandparent in the same room 😅
@AbSSChem
English
@jcesar_dasilva Do you count the phase contrast work at BM18 as "coherence" ? They seem to rely on the small source ...
English
@jonwright76 Hi Jon, definitely yes. I am not saying it is not, but only that the advertisement on coherence was too much without real investment in it afterwards. And as you can see below in the 3 deliverables of phase II in the orange book, coherence appears quite often, but not only.
English
People spend > 100 million euros/dollars to upgrade synchrotron facilities with the only motivation of offering more coherent X-ray beams, but, in the end, none of the techniques offered need coherence, despite the existence of many. Complete lack of investiment strategy here.
GIF
English
Actually the lattice is simply a pictorial representation of the mathematics of periodicity defined by translation operators. It has no physical existence. Any molecular motion is in the crystal.
SupraChem@Sureshan Group@SureshanLab
@MikeGlazer1 lattice is array of points in 3D space with in the boundary of the crystal. Right? What would you call molecular motion in that space?
English
jonathan wright أُعيد تغريده
We're looking for a beamline scientist or engineer to join us!
We offer a stable job in industry, where you'll have a chance to see lots of beamlines all over the world.
jjxray.dk/vacancy-for-a-…
English