All Questions
Tagged with inorganic-chemistry crystal-structure
111
questions
4
votes
1
answer
87
views
Brilliant fluorescent properties of Na2S(x) obtained from Na2SO3 or Na2S2O3
When $\ce{K2SO3}$ or $\ce{Na2SO3}$ is heated strongly by any method (in a flame, in an electric arc, on a metal plate in an induction heater), the resulting residue should be a mixture of $\ce{Na2SO4/...
- 115
3
votes
1
answer
105
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Does CsBr have BCC lattice or cubic?
Everywhere I see on the internet, it says BCC, but my professor still says "it is cubic lattice, no matter which book/website might tell you otherwise".
The argument was that for deciding ...
4
votes
2
answers
686
views
Can “hydrates” of crystals form with other molecules?
It is well known that copper sulfate, sodium sulfate, et al crystallize with 5,10 water molecules of hydration, locked in their crystal lattices. Is it possible to have other molecules instead of ...
- 57
-2
votes
1
answer
25
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Formation of cocrystals troubleshootin
In cocrystal formation what would the possible reason be for the precipitation of an amorphus oily precipitate not suitable for PXRD? Solvent was DMF and the reagent were L-thyroxine and ...
3
votes
2
answers
143
views
Crystal structure of tin tetraiodide
I was looking at the molecule of $\ce{SnI4}$ and how its structure looks like in its crystal lattice:
Wikipedia.de says its crystal lattice is of the fcc (ccp) type (for the iodine atoms), which ...
- 383
4
votes
2
answers
511
views
What determines how easily a gas can diffuse into a crystal structure?
I have been told by a metallurgist that the reason a factory oxidizes the iron oxides in ilmenite before reducing them down to pure iron, is that the the products of this have a more spacious crystal ...
- 301
4
votes
2
answers
190
views
Crystal structures exhibiting dimeric arrangement of tetrahedrally coordinated cations
I am looking for inorganic crystal structures that exhibit tetrahedrally coordinated cations arranged in a vertex-sharing dimer arrangement, where the cation - shared vertex - cation angle is close to ...
0
votes
1
answer
92
views
Why does FCC crystalline forms form hexagonal crystalline structures during CVD?
During the CVD process, Copper and Nickel which are both Face Centered Cubic crystalline structures are used as substrates for shaping hexagonal atomic structures such as graphene and hexagonal Boron-...
- 51
2
votes
1
answer
55
views
Why and how are mullites (and in extension solid solutions) formed and how are their formulas conceived as opposed to regular crystalline solids?
From doing more Phase ID for XRD on aluminosilicate based coal fly ash samples, I've seen mullite phases appear a few times which have the non-stoichiometric chemical formula $Al_{4+2_x}Si_{2-2x}O_{10-...
- 500
4
votes
0
answers
50
views
Why is reported effective pore size smaller that the one declared in the name of the molecular sieve type X?
The molecular sieve type is often coded with <number><letter> combination, where <number> specifies the pore ...
- 38.4k
6
votes
1
answer
933
views
Number of bridge oxygen atoms in a silicate mineral
Total number of oxygen atom(s) which act(s) as bridge between any two silicon atoms in a mineral with composition $\ce{MM’Si3O_x}$ $(\ce{M}$ is the divalent metal ion and $\ce{M’}$ is the tetravalent ...
- 342
-1
votes
2
answers
142
views
Why does density decrease when pressure is increased on an NaCl type lattice?
I was told that the effect of pressure on an NaCl type structure would make the atoms come closer and therefore change the type to CsCl type making Z (no of atoms per unit cell) go down, hence density ...
- 19
6
votes
1
answer
515
views
Why does Samarium have such a large c-axis lattice constant? (>26 Å) Are there significantly larger lattice constants of the elements?
Figure 1.2 on page 12 of The Structure of Rare-earth Metal Surfaces linked below shows a repeating stack of hexagonal layers arranged as A B A B C B C A C... and several sources give the c-axis ...
- 5,900
6
votes
4
answers
2k
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Given a CIF (crystallographic interchange format) file (and thus cartesian atomic coordinates), how can you find the bonds between atoms?
Applications like Vesta show bonds when viewing a CIF file; how could one algorithmically find all bond pairs?
Here is an example CIF file:
...
- 171
4
votes
1
answer
650
views
Why can't the Fajans' rule and lattice energy theory be used to explain the difference in thermal stability of magnesium and calcium carbonates?
$\ce{CaCO3}$ is more thermally stable than $\ce{MgCO3}.$ I do understand that a larger cation would be able to stabilize a larger anion to a greater extent, but why can't we use Fajans' rule or ...
- 41