Stefano Canossa

@stecanossa.bsky.social

Reticular chemistry, total scattering & Fourier transform enthusiast • Research professor at Ewha Womans University (Seoul 🇰🇷 ) https://orcid.org/0000-0002-6817-0810 https://github.com/stecanossa

$A diffraction image showing a saturated Bragg reflection surrounded by speckle-containing rings, in an overall very grainy diffraction pattern.$

A detail of Olex2 interface displaying the R1 and wR2 factors, with the first one reading "586.69%"

A clean peaktable from CrysAlisPro, showing perfectly spaced systematic absences.

A video showing the atomic tile builder user interface, and its simple use to load a cif file and create a tile out of it, with just a few clicks.

A cascade of silver spheres frozen in time. Perfectly ordered within a fixed lattice. L divide artwork between two escalators going through 4 floors.

A couple of models built with ball and sticks: a truncated octahedron and a pair of eclipsed grapheme sheet structures.

An elegant young girl from centuries ago holds a horrible beast, above the girl, the label "the cute little crystal". The beast is labelled "the structure"

Slideshow of the new FourierTiler functionalities, showcasing variations of mosaicity in sharp patterns, change in gaussian smoothing, Patterson functions, pair distribution functions, and total scattering patterns.

A play of laser light reflecting on the clouds.

$a smeared and diffuse diffraciton pattern made by tuning gaussian smoothing and azimuthal smearing in Fourier Tiler.$

Four different patterns calculated from a MOF-5 simulant tiling using Fourier Tiler. The four patterns are computed by considering a mosaic orientation spread of 0, 3, 10, 90 degrees. As a result, the pointy Bragg peaks smear into arcs, large lines, and eventually homogeneous circles, while the diffuse scattering features from missing cluster defects are not recognizable anymore, if not for a bright blob in the centre.

In this video, a tiling is created to produce a FT squared pattern. At that point, the function for displaying the simple FT magnitude is activated, followed by the functions for using a logarithmic intensity scale for the visualization.

A side-by-side comparison of a pattern produced by COF-366 tiling simulant, and actual COF-366 atomistic model. The patterns differ mostly in intensities magnitude, and not in their distribution or the shape they form.

$A series of cracks in a wooden pillar form parallelepipeds with similar sizes, and an overall fractal structure of cracks and sub-cracks.$

Fourier Tiler GUI interface with all the available options on display.

disordered alternation of white squares tilted to the right or to the left.

A condensed picture taken from the referenced article (Fig. 4). A more detailed description of its details can be found in Section 3 and in the caption of the Figure in the same article.

A yellow small coffee mug hosting a small round cactus with long, healthy spikes.

A beautiful view of the new Institute for Multiscale Matter and System at sunset, with the description of the job posting:

"Fully funded PhD positions available at Ewha Womans University-Institute for Multiscale Matter and Systems, jointly supervised by Prof. Hoi Ri Moon and Prof. Stefano Canossa. Selected candidates will work at the new IMMS institute supported by the National Research Laboratory 2.0 program. Here, they will join an international team in harnessing structural complexity to uncover uncharted territories in the chemistry of porous materials, focussing on one or a combination of the following topics:
1- Design and applications of defect-engineered metal–organic frameworks (MOFs).
2- Development of automated and autonomous laboratories for reticular materials discovery.
3- Design and applications of MOF glasses and complex heterostructures.
4- New total scattering methods based on X-ray and electron crystallography.

A tall ring of interpenetrated cubes, made of stone.

A road in Seoul city centre, covered in white, fully blossomed cherry trees.

Detail of a bronze sculpture showing triangles joined in an aperiodic pattern, reminiscent of a glassy atomic structure.

A wall of square grey stones, but everything is tilted by 45° for some cool reason.

A wall of rectangular stones, well packed despite having all different size, larger at the bottom, gradually smaller towards the top. Many light grey, some sand-yellow with a rose hue.

A patchy version of the quoted pattern, where the selection of the origin of the tile has two options, creating a domain structure.

A scottish Tartan pattern made of red, yellow, white and blue stripey bands on a dark green background.

A bluish-green nebula-looking universe of Bluesky accounts, with me in the periphery of the "Nebula Research Cluster"

The sequence of preparation of a jam tart, and the final product. Above, the tart is prepared by partitioning the area in 6 parts, and filling them with, in order, blackberry, apricot, blackberry, apricot, blackberry, apricot jams. a few decorative streaks of italian "frolla" butter dough created a nice 6-fold woven pattern.

A catcha test with QOQW to be guessed: I guessed QOQE by mistyping and the test succeeded anyway ...

A collage of image to commemorate a successful crystallography workshop at the University of Wroclaw, including a smiling Wojtek bringing a bunch of delicious polish donuts to all participants (me included :P)

The wall of the Pinta craft beer pub in Wroclaw, showing a colourful mix of beer listed on a blackboard with artistic pictures to represent every beer. The signature of a good beer tasting venue.

A tiling of cookies inspired by the works of M. C. Escher. Each cookie resembles a flying bird with googly eyes and a very tasty look! the original image was modified by adding symbols for the symmetry elements, highlighting the presence of three-, six-, and two-fold rotation axes.

A thick-paper calendar sheet with a Photograph printed on it. The picture shows a bunch of ants collaborating, walking along a white rough surface without a recognizable order, and apparently marching North-East.

A huuuge Moka coffee pot, roughy 1.2 meters tall, with a shocked me behind it.

$A word cloud of my most used terms on Bluesky posts. Top 10: 1.structure 2. those 3. crystal 4. space 5. find 6. structures 7. hope 8. symmetry 9. mean 10. diffraction$

A chocolate replica of the Nobel prize medal.

The stage of the Nobel Prize Concert, at the Stockholm Konserthuset.

Susumu Kitagawa's presentation at the Nobel lectures. The slide reads "The usefulness of useless"

Just a small coffee in a paper cup, nothing seems special about it.

Plane group interpretation of the original tiling in the main post. Dashed lines reveal the unit tile, and a white-coloured tile shows the arrangement of tiles inside the repeating unit: a composition of squares and rectangles with a left-handed 4-fold axis.

An alt-text statistics of my posts, showing 98% of the images I have posted having alt text.

$A square divided in four squares, each containing strands of violet-and-blue light - some like rays, some like diffuse bands - separated by darker shady regions. Overall, these lights look like refractions coming from the centre of the image, which gets darker and darker in approaching the very middle.$

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.

A beer with an oddly creamy, light-custard looking colour

A Hyperbolic tiling of triangles, with variable colours from a grey-dark blue to a light bluish green.

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.

$A graph showing the process of single crystal diffraction analysis as a semicircle, starting from a crystal, and continuing with scattering data, Bragg intensities, average structure, and at the end average model.$

Screenshot of the "Windows update > Advanced options" window, where all sub options are turned off.

The first three references in my tutorial review, respectively citing the foundational works by Robson, Kitagawa, and Yaghi in the field of MOFs.

A picture of me with Prof. Omar Yaghi and Stefan Wuttke, in Omar's office.

A Wikipedia entry about the typical italian snack "Taralli" starts with the sentence "Taralli are toroidal italian snack foods, (...)"

A manhole cover, where dots on a square grid are smoothly deviating from the square lattice, resembling a phonon in a crystal.

A difference Fourier map shows red blobs surrounded by green-red-green etc. ripples, in an overall triangular symmetric pattern.

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.

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.

$A python script reads: from pymatgen.core import Molecule from pymatgen.symmetry.analyzer import PointGroupAnalyzer ## attention! the following file should contain structure in cartesian ## coordinates with sensible distances: no fractional coordinates allowed! mol = Molecule.from_file("clu-lin_0p5_0_0.xyz") pga = PointGroupAnalyzer(mol) point_group = pga.sch_symbol multiplicity = len(pga.symmops) print("Point group (Schoenflies):", point_group) print("Multiplicity (number of operations):", multiplicity) for i, op in enumerate(pga.symmops, start=1): print(f"{i}. {op.as_xyz_str()}")$