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!


P-1 – Success

After tweaking the deuterium atomic radii the print seemed to work well – although I am starting to discover the limitation of my poor Snapmaker is in the post-print. The scaffold is proving to be very difficult to remove without damaging the print.

A slightly battered print of the P-1 space group

Still – I’m happy with the .stl file so feel free to print out your own version! I’d recommend a soluble scaffold or a breakaway filament.

If you want to have a go yourself – check it out at:


Let me know how you get on if you give it a go!

P1 – Success (almost!)

We have success! The project begins properly now! After several failed attempts (check out the failures category for more details) we have our first space group print:

As you can see – although the unit cell printed, it was so thin that it snapped easily in post clean-up

Sadly my ham-fisted approach to cleaning up led to a couple of the unit cell axis being snapped. I don’t think you’d have that problem if you scaled it up even more than the 850 % that I used or used a breakaway filament such as PVA for the scaffold. Sadly I only have a single nozzle on my snapmaker so that is just a dream for me!

If you want to have a go yourself – check it out at:


I would love to see how yours comes out! Good luck and stay tuned for P-1 (it’s printing at home as I type.. Gulp!)