P2 – Thomasclarkite-(Y)

Welcome back! Two down, 227 to go. Gulp.

The first two space groups were pretty simple prints (although my post-print work was a little shocking – if only someone would buy me a duel nozzle printer or an SLA printer… 😉 ) and I am really happy with how they turned out.

However, now things are getting serious.. We’ve moved out of the asymmetric territory of triclinic space groups and are now entering the heady heights of the monoclinic crystal system. Unlike triclinic where none of the sides or angles of the unit cell are equal, in the monoclinic system a, b and c are not the same distance, but the angles α and β are equal to 90 degrees.

P2 is the simplest of the space groups in the monoclinic crystal system and the fantastic people at: https://crystalsymmetry.wordpress.com/230-2/ selected ‘Thomasclarkite’ as their example for it.

Thomasclarkite is a newly (1998) discovered sodium containing rare-earth element carbonate, identified by J. D. Grice and R. A. Gault in Mont Saint-Hilaire, Quebec. Oh how I would love to go mineral hunting there one day! Sadly my one major mineral hunt ended with me falling down a cliff, but that is another story..

The .cif (from: http://rruff.geo.arizona.edu/AMS/minerals/Thomasclarkite-(Y) ) outputs the following in crystalmaker:

Thomasclarkite-(Y) with carbon, sodium, oxygen and yttrium in black, yellow, red and light blue respectively. Water positions are dark blue/grey.

Looks pretty but not printer friendly at all – firstly those floating water positions have to go and we need to increase both the bond sizes and unit cell to be able to print this..

Bumped up the unit cell to crystalmaker’s max (blue line, 10 pixels), changed the hydroxides to pink (wish I had neutron data to play with – then we’d see the hydrogen positions), removed the water and increased the carbon atomic radii to 0.75 angstroms. I’ve also increased the stick bonds to 50% the smallest atomic radii and we get the below:

Thomasclarkite-(Y) with water positions removed.

I think I’m going to take the executive decision not to print water positions (or any other absorbed molecules) unless they are part of the structure. I think it would be too tricky to keep them in for my Snapmaker – although I’m happy to upload .stl files if you want to give it a go – just let me know!

Importing the .stl into the snapmaker3D slicing software we get:

Scaled up to 500 % and rotated in y by 90 degrees

Only 7 hours! Although it is looking flimsy – I’ll give it a go but I’m not sure about this one at all.. Especially considering my record so far with the post-print work..

Check back later to see how it went!


Zeolite A (LTA)

Tl:dr: Here is the printable STL:

Now I know I said this was about the naturally occurring zeolites (hydrated aluminosilicates) but I couldn’t carry out this project without a nod to zeolite A (Linde Type A). Possibly one of the most famous zeolites as it is one of the earliest synthetic (no natural version) zeolites discovered.

The first synthesis of a zeolite was reported by St. Claire Deville in 1862 with the formation of levynite.[1] It wasn’t until the incredible work of Richard M. Barrer that things really took off however. He classified the zeolites known at the time by molecular sizes [2] and in 1948 presented the first definitive synthesis of zeolites, an analogue of mordenite [3] and an at the time unknown new synthetic zeolite, which was later identified as the KFI framework. [4]

Barrer’s work inspired Robert M. Milton and Donald W. Breck (both of the Linde Division of Union Carbide Corporation) to investigate zeolite synthesis in search of new ways to separate and purify air. They discovered the new types of synthetic zeolites A, X and Y – which were then commercialised by Union Carbide.

The great thing about zeolite A is that you probably have some in your house right now, it has been extensively used as a water softener in detergent (those pore sizes are just the right size to exchange limescale causing calcium for sodium).

So to the print!

Armed with a crystallographic information file (cif) from the brilliant International Zeolite Association website:
http://europe.iza-structure.org/IZA-SC/material_tm.php?STC=LTA (accessed May 2019)

It was pretty easy to load it up into crystalmaker, however from experience I know that the ball and stick model doesn’t print too well so with a little help from the guys at
http://crystalmaker.com/crystalmaker/video-tutorials/index.html (their video tutorials are great – to do this I used the ‘building massive polyhedra’ video). I managed to create the following model:

Massive polyhedra view of zeolite A, sodalite beta cages in pink, and d4r (double 4 ring) in grey

If you are not used to working in 3D with zeolites, this doesn’t quite get across how they are formed of pores and channels connected by secondary or composite building blocks (the sodalite beta cage and d4r) so I’ve produced a little gif below to help.

Rotation movie of zeolite A massive polyhedra

Much better, these pores and channels are what make zeolites so useful and special, they can trap things (like gases or radioactive isotopes), sieve things (different sized and shaped molecules) and carry out ion exchange.

As this structure is fairly simple I could convert it into a stl and load it into snapmaker with no problems.

Scaled up to 300 %

A good 7 and a half hour print, so time to go to some friends for lunch and go for a walk in a forest..

Ta da!

Looking good – sorry for the mess around it.
After a quick clean up

Success! One out of around 50 done (depends which other synthetic zeolites I print..) Printed really well and easily, a little trouble with the overhangs on the sodalite cages but otherwise I’m very happy.

STL file:

[1] H. de St. Claire Deville, Comptes Rendus Acad. Sci, 1862, 54, 324

[2] R. M. Barrer, J. Soc. Chem. Ind., 1945, 64, 130

[3] R. M. Barrer, J. Chem. Soc., 1948, 2158

[4] R. M. Barrer, J. Chem. Soc., 1948, 127