With this star-like atomistic ensemble (it’s the #crystal structure of corundum viewed along the c axis) I wish you all a beautiful holiday season and a new year of peace and happiness.
We’ve just released chapter one of our course “The Fascination of Crystals and Symmetry” on YouTube:
Further chapters will be published probabaly weekly.
The WordPress.com stats helper monkeys prepared a 2015 annual report for this blog.
Here’s an excerpt:
The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 13,000 times in 2015. If it were a concert at Sydney Opera House, it would take about 5 sold-out performances for that many people to see it.
Click here to see the complete report.
We are happy to announce that the space group list project is now completely accessible and incorporated into CrystalWorks.
CrystalWorks is part of the National Chemical Database Service (CDS) of the Royal Society of Chemistry (UK) and comprises crystallographic data of organic (CSD), inorganic (ICSD), and metallic (CrystMet) compounds.
The CrystalWorks link on this page provide full display functionality for all 230 structures. In particular full interactive structure display is available via JSmol (see screenshot below). This provides useful features which are complementary to those of VESTA.
The WordPress.com stats helper monkeys prepared a 2014 annual report for this blog.
Here's an excerpt:
The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 8,300 times in 2014. If it were a concert at Sydney Opera House, it would take about 3 sold-out performances for that many people to see it.
Click here to see the complete report.
today Chapter 5 of our course has been activated!
We hope, you are all doing well!
In this week we will practise the handling with the International Tables a little further. But in contrast to staring only at circles and commas we will additionally look at real world crystals and some of their symmetry and physical properties. And you can be curious about the story of one of the most thrilling scientific discoveries of the last century: the discovery of quasicrystals by Dan Shechtman.
Looking forward to meet you at class and in the forum!
Frank and Michael
#196 – update
Tomas, one of our readers of this blog, identified an error concerning the space group list project. As he correctly pointed out, the entry of #196 (F23) was wrong as the coordinate set of the solvent free zink sulfate clearly shows F-43m symmetry (#216).
I have informed the FIZ Karlsruhe and they will delete this wrong entry in their ICSD database with the next update/release.
So, the new (approved) entry for #196 is:
tetrakis((18-Crown-6)-thallium) tetrachloro-manganese bis(tetrachloro-thallium)
Coordination Characteristics of Divalent Tetrahedral (Td and D2d) Tetrahalometalate Anions of 3d Elements and Solid-State 18C6 Reorientations
N.S. Fender, S.S. Finegan, D. Miller. M. Mitchell, I.A. Kahwa, F.R. Fronczek
Inorg. Chem., 1994, 33 (18), pp 4002–4008
MnCl4 tetrahedra (purple)
TlCl4 tetrahedra (blue)
Also the poster of the Space group list project was updated, which you can download here:
in this week we will introduce a very special class of crystalline materials, which are called Metal-Organic Frameworks or short MOFs. Research interest in this kind of materials has intensified immensely over the last decade. As MOFs are also the field of study of our research group, telling you something about these very special crystals is a matter of heart for us.
MOFs are comprised of inorganic and organic secondary building units. We will take a look at different variations of how these secondary building units can be assembled together and we will introduce the principles of classification of these network-like assemblies.
We provide several crystal structures of MOFs as VESTA files, in order for you to be able to get familiar with the structural features of MOFs at the atomic level. (You can find a tutorial on how to obtain and install VESTA in Unit 2.7)
At the end of this chapter we will be prepared for the next week, in which we will introduce software (called TOPOS and Systre) that allows investigating, determining and classifying the topology of Metal-Organic Frameworks in a systematic way, i.e. to answer the question what are the underlying nets (= linked vertices) and how can we precisely describe them?
Enjoy the beauty of porous crystals!
Michael and Frank