Stefano Canossa
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stecanossa.bsky.social
Stefano Canossa
@stecanossa.bsky.social
660 followers 390 following 890 posts
Framework materials, total scattering & Fourier transform enthusiast │ Curator of patterns and alternative crystallographic teaching at behance.net/specialdefects

https://orcid.org/0000-0002-6817-0810
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stecanossa.bsky.social
And here we have our Fourier transform nr. 58! As far as I'm concerned, perhaps the most enigmatic and unexpected spectrum so far... anyway, quite a spectacle! #BraggYourPattern #Fouriertransform #crystallography

As always, more on behance.net/specialdefects and instagram.com/specialdefects
A square divided in four squares, each containing strands of violet-and-blue light - some like rays, some like diffuse bands - separated by darker shady regions. Overall, these lights look like refractions coming from the centre of the image, which gets darker and darker in approaching the very middle.
November 9, 2025 at 4:06 PM
stecanossa.bsky.social
While playing around with shapes I discovered another optical illusion: it looks like it's tilting while going inwards, doesn't it... 🧐 it's not — check the corners. Its Fourier spectrum is really unlike anything I've seen so far... will post it soon. #BraggYourPattern
Spiral of segments resembling a whirlpool. Each segment has a different shade of grey, creating an optical illusion where the sequence of segments appear gradually tilting.
November 9, 2025 at 12:22 PM
stecanossa.bsky.social
I actually had something similar a while ago... was also quite puzzled from the colour. But it was not too bad -- not sour though, at all
A beer with an oddly creamy, light-custard looking colour
November 7, 2025 at 7:19 PM
stecanossa.bsky.social
As always, here's the real-space picture 🙇 You can find many more pairs on www.behance.net/specialdefects
A Hyperbolic tiling of triangles, with variable colours from a grey-dark blue to a light bluish green.
October 16, 2025 at 9:10 PM
stecanossa.bsky.social
Time for a new 57th entry in my #Reciprocart gallery! This time we look at the frequency spectrum of a Hyperbolic tiling of triangles 📐 Unsurprisingly (for the experienced) it's a bunch of lines... but the hexagonal symmetry is visible if one looks close enough 🧐 #crystallography #Braggyourpattern
A nearly isotropic pattern of lines irradiating from the centre. The colour scheme is a fresh combination of teal, light violet and blue on a white background.
October 16, 2025 at 9:05 PM
stecanossa.bsky.social
Every now and then I might post important concepts on single crystal diffraction analysis from my recent review. Today, this wrapped-up version of figure 1 reminds us what we lose in the process, and what we actually gain at the end: a model 💎

#crystallography #MOFs

pubs.rsc.org/en/content/a...
A graph showing the process of single crystal diffraction analysis as a semicircle, starting from a crystal, and continuing with scattering data, Bragg intensities, average structure, and at the end average model.
October 16, 2025 at 4:53 PM
stecanossa.bsky.social
You sure you did not have the automatic update option active? I remember it was on by default on mine, but once I changed it to "off" I feel like my laptop's Lord, granting update rights whenever I please 😑
Screenshot of the "Windows update > Advanced options" window, where all sub options are turned off.
October 16, 2025 at 12:08 PM
stecanossa.bsky.social
Well, well... who wants to be cited at the beginning of one of my papers next year? #NobelPrize
The first three references in my tutorial review, respectively citing the foundational works by Robson, Kitagawa, and Yaghi in the field of MOFs.
October 8, 2025 at 12:46 PM
stecanossa.bsky.social
I guess it's time to dust off a celebratory picture of my memorable visit to Omar's lab a few years back, with my good friend Stefan Wuttke 😊 #MOFs
A picture of me with Prof. Omar Yaghi and Stefan Wuttke, in Omar's office.
October 8, 2025 at 10:45 AM
stecanossa.bsky.social
"Taralli are toroidal" is my current favourite fact as far as phonaestetics goes.

#topology
A Wikipedia entry about the typical italian snack "Taralli" starts with the sentence "Taralli are toroidal italian snack foods, (...)"
October 7, 2025 at 9:31 AM
stecanossa.bsky.social
Someone in Verona decided to make "phonon-ish manhole covers" - Approved 👌🏻 #Braggyourpattern
A manhole cover, where dots on a square grid are smoothly deviating from the square lattice, resembling a phonon in a crystal.
October 2, 2025 at 2:48 PM
stecanossa.bsky.social
When diffraction data has low resolution you can always make some Rorschach Tests out of it. #crystallography #Braggyourpattern
A difference Fourier map shows red blobs surrounded by green-red-green etc. ripples, in an overall triangular symmetric pattern.
September 30, 2025 at 9:27 AM
stecanossa.bsky.social
In case someone was wondering about the origin of those frequences... 😌 I admit this is pretty challenging to decipher in terms of real-space to reciprocal-space relationship, without knowing know how it is made. #FourierTransform #Crystallography #Braggyourpattern
An aperiodic tiling formed by the intersection of two square tilings of squares, one tilted by 43° with respect to the other. Many shapes are visible, diamonds, triangles, irregular octagons, and many other.
September 28, 2025 at 8:21 PM
stecanossa.bsky.social
My fellow #FourierTransform enthusiasts, here's a new entry in my collection ready for you, nr. 56! The real-space picture is an intersection of two tilings of squares, one tilted by 43°. Moiré pattern? Definitely related 💯

As always, you can find the high-res pair at behance.net/specialdefects
A collection of bright yellow spots starts from the centre of the picture, from the strongest, central one. Clearly not periodically arranged, they have a point-symmetry evident since 4 equally spaced lines of stronger spots irradiate from the centre of the image. Between them, additional smaller spots form geometrical patterns vaguely resembling the fourier transform of an aperiodic crystal. The background colour alternate dark blue and soft teal, whose calm feeling contrasts the energy present in the bright yellow spots, looking like tiny fireflies.
September 28, 2025 at 1:29 PM
stecanossa.bsky.social
I made a tiny script, it seemingly works but the output is a littel weird.
A python script reads: from pymatgen.core import Molecule from pymatgen.symmetry.analyzer import PointGroupAnalyzer ## attention! the following file should contain structure in cartesian ## coordinates with sensible distances: no fractional coordinates allowed! mol = Molecule.from_file("clu-lin_0p5_0_0.xyz") pga = PointGroupAnalyzer(mol) point_group = pga.sch_symbol multiplicity = len(pga.symmops) print("Point group (Schoenflies):", point_group) print("Multiplicity (number of operations):", multiplicity) for i, op in enumerate(pga.symmops, start=1): print(f"{i}. {op.as_xyz_str()}")
September 26, 2025 at 6:32 PM
stecanossa.bsky.social
He knew 🍃 #crystallography #totalscattering #老子
A Ming era portrait of Laozi shown together with some words from the opening of its renowned Tao Te Ching, modified in the total scattering context. The words say: "The structure that can be modelled is not the real structure; the scattering that can be simulated is not the real scattering"
September 9, 2025 at 9:32 AM
stecanossa.bsky.social
I've forgotten the protagonist)
A glass of hazy IPA beer, cloudy pale orange tone
September 5, 2025 at 4:40 PM
stecanossa.bsky.social
Yet another nerdy hazy I've just found... Have a hoppy weekend! Cheers
A craft beer label reads "Gravity well - quantum saturation"
September 5, 2025 at 4:37 PM
stecanossa.bsky.social
"Good day Sir, here are today's options. Would you like anisotropic peak broadening, diffuse streaks, superstructure peaks, or twinning?" "Yes, please"
#Crystallography #totalscattering #TheCuteLittleCrystal
An intricated single-crystal (?) reconstruction of reciprocal space shows main Bragg peaks, streaks crossing them, and satellite peaks arranged in tiny crosses between the main Bragg peaks.
September 3, 2025 at 12:05 PM
stecanossa.bsky.social
Wow... it seems that the Fourier force is strong in this Gnome!
Happy 10th birthday, little friend from @rigakuoxfordxrd.bsky.social

#ROD10atECM #Fouriertransform #crystallography #ECM35
A little bronze gnome holding the Oxford diffraction logo in his hand, in front of his face. In front of him, a beautiful blue pattern appears on a dark screen: the Fourier transform (diffraction pattern) of the logo!
August 27, 2025 at 1:39 PM
stecanossa.bsky.social
"Success for all", from his University's motto to a life that changed everyone else's... Today's #ECM35 starts with a lecture filled with emotions and anecdotes by Isabel Usón, remembering George Sheldrick #crystallography
The initial slide of a presentation on George Sheldrick, with his image as a young student. The title reads "George Sheldrik's SHELX: Success for all" by Isabel Usón
August 26, 2025 at 7:03 AM
stecanossa.bsky.social
The 35th European Crystallography Meeting is approaching fast, and so is the incredibly disordered session (in a good way 🙂‍↕️) I and @hannabostroem.bsky.social will chair! Come meet our awesome invited speakers Emily Meekel and Martin Schmidt, as well as our selected contributors! 🌟 🙌
An advertisement slide for the Microsymposium nr.24 at the coming European crystallography meeting ECM35. The invited speakers are Emily meekel with her talk "Tuning the local structure of isoreticular porous materials", and Martin Schmidt, with "Nanocrystalline organic compounds: structure determination by a global fit of the pair-distribution function"
August 21, 2025 at 7:33 PM
stecanossa.bsky.social
Weird.... fixed it
A request by Elsevier journals about race identity is corrected by replacing "race" with "ShelX command", and listing among the possibilities "DANG, ACTA, SUMP, RIGU, SADI/SAME, EXTI"
August 20, 2025 at 5:54 PM
stecanossa.bsky.social
A famous meme depicts a smiling, a bit clueless guy looking at a butterfly and asking himself "is this a butterfly?". The meme has been modified to turn the question into "is this correlated disorder?", referring to the local order of coloured balls in the main picture.
August 20, 2025 at 9:02 AM
stecanossa.bsky.social
... and its beautiful #Fouriertransform, completing #specialdefects pair nr. 55 👾 Those who got a little used to how the Fourier space works might guess (correctly) that this looks essentially like the FFT of a single 12-pointed star ✍️ #BraggYourPattern #TotalScattering #Crystallography
Fourier transform of the quoted image. Bright strands raidating from the centre, oscillating in intensity along the lines, and bumping on the image sides. The colour scheme is created to show these lines as sparks from a firework, with sharp white-yellow-brown gradients.
July 5, 2025 at 11:39 AM