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Questions tagged [crystal-structure]

In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms or molecules in a crystalline liquid or solid.

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Is the acceleration of the low-temperature allotropic conversion of β-form white tin by the presence of α-form grey tin really considered catalysis?

discussion of the allotropes of sulfur in Melting point of sulfur and comments below reminded me of Napoleon's buttons, cf. Tin pest; Allotropic transformation. That section in its entirety reads: At ...
uhoh's user avatar
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Undiscovered kinetically-hindered metastable phases

The majority of solid chemicals have multiple meta-stable phases. This means that there are multiple different crystal structures that are kinetically stable. For example, aragonite and calcite are ...
Kevin Kostlan's user avatar
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Would fluorides stabilize zirconia?

The reason for zirconia's cubic and tetragonal phases not being stable is that the cation-anion ratio is too small for proper contact between ions. One way is to use other oxides that have a bigger ...
user145034's user avatar
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Small-Angle X-Ray Scattering of Bulk Polymers

Does anyone have any recommendations on how to get useful information from SAXS of polymers when the system is not dilute? This is the type of data we're working with: My understanding is that since ...
polythenesam's user avatar
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Crystal lattice structure from single crystal x-ray diffraction pattern

Is there a good reference describing the inverse problem of determining the crystal lattice, unit cell etc., from a single crystal x-ray diffraction pattern and chemical composition? I am looking for ...
S R's user avatar
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Constituents of LaI2 [closed]

An ionic solid $\ce{LaI2}$ shows electrical conduction due to presence of which anions and cations?
WATCHER's user avatar
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growing flawless NaCl crystals

Simple experiments on the internet show how to grow salt (NaCl) crystals, but the crystals are small and flawed. Several companies sell flawless optics, like windows, made of NaCl, which are ...
Michael's user avatar
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1 answer
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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 ...
Sudarshan Kulkarni's user avatar
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Why Green Solution After Putting Bismuth Antimony in Nitrogen Acid

I am in a physics lab studying dislocation, and we submerged a bismuth antimony sample in nitrogen acid (about 50% concentration, if I remembered it right) as the first step to etch it. There were ...
Yuting Z's user avatar
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Why don't Zn, Cd, Mn and Hg have more than one metallic structure at normal temperature, while other d-block elements do?

It's been given in my book, that "With the exceptions of Zn, Cd, Hg and Mn, they have one or more typical metallic structures at normal temperatures." But, why this exception?
saromitha kumar XA mem's user avatar
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3 answers
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Can any compound form into an amorphous solid?

I am curious whether it is possible or not to make any solution of a specific compound into a crystal lattice or into an amorphous solid? I know that crystals form under specific conditions but seem ...
Brian Blumberg's user avatar
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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 ...
Alex Wang's user avatar
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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 ...
luka racic's user avatar
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6 answers
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Does an ionic bond have a dipole?

Is an ionic compound like NaCl considered a dipole? It has a positive side (Na+) and a negative side (Cl-). Or is it true that an ionic bond does not have a dipole because a dipole is, by definition, ...
Chemistry Boi's user avatar
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2 answers
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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 ...
Mäßige's user avatar
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Why does this lysozyme powder not look crystalline?

I am very new to protein crystallography and visualization. I have been asked to take photos through an optical microscope of the lysozyme powder directly as-is from the supplier. I suspended some of ...
Mack's user avatar
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Why does KCl have FCC structure instead of BCC?

I have this table here. \begin{array} {|r|r|}\hline \text{Radius Ratio} & \text{Coordination number} & \text{Type of Void} \\ \hline <0.155 & 2 & \text{Linear} \\ \hline 0.155-0....
Aditya Kumar Panda's user avatar
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2 answers
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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 ...
user110391's user avatar
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How to express the lattice parameter of NaCl in terms of ionic radii? [closed]

In the $\ce{NaCl}$ lattice, $\ce{Cl^-}$ takes the FCC configuration, and all the voids at the edge and body center are filled by $\ce{Na^+}.$ So, do we calculate the edge length of unit cell $a$ as $$...
Kutubkhan Bhatiya's user avatar
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Copper sulfate pentahydrate crystal structure [duplicate]

I am interested in what exactly the structure of copper sulfate pentahydrate crystal is like. In the wikipedia, it consists of copper and sulfate strand with 4 water attached to each of the copper ...
aaa's user avatar
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3 votes
1 answer
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Temperature Dependence of Crystal Formation in Storm Glass

The storm glass is an interesting historical device which claims to be able to predict the weather (for example, clear liquid implies fair weather, murky liquid implies rainy weather and large flaky ...
Tom's user avatar
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Is this a Pyrite crystal cube? [closed]

There is a metallic shine on it that does not clearly show in the photo This cube weighs 458g Dimensions: 55mm H x 45mm W x 39mm D Is this a Pyrite cube? Thank you
Judy Netel's user avatar
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Why does gallium expand on solidification

I've heard that Ga exist as Ga2 molecules in its crystal lattice. Does that have anything to do with expansion of Ga while solidifying? Why and how does it actually expand?
Neet aspirant's user avatar
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Converting Quartz data from one (P3221) space group to another (P3121)

For my studies, I’ve done a lot of work on coal fly ash QXRD QPA on TOPAS which has been a fun and interesting challenge. Apart from theory reviewing, a lot of my learning so far has come from a prior ...
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What does the 'S' stand for in base-centered cubic crystals and Bravais lattices?

The 'I' used for body-centered systems is for the German word Innenzentriert and the 'F' for face-centered is for Flächenzentriert, also German but what about the 'S' for a, b, or c base-centered ...
Kurt Hikes's user avatar
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Why are certain lattices compatible with only certain point groups and not all point groups?

I will limit this discussion to 2 dimensions for ease of intuition. My understanding of the 17 crystallographic plane groups is that these 17 groups represent all the possible symmetry groups of any ...
SalahTheGoat's user avatar
4 votes
2 answers
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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 ...
AChemicalEntity's user avatar
6 votes
1 answer
435 views

Do hydration (as in "solvation") and "hydration" of salts refer to the same phenomenon?

I've come across two use cases of the word "hydration", presented to me as distinct topics: Solvation is the process of reorganizing solvent and solute molecules into solvation complexes ...
Arham Jain's user avatar
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2 answers
555 views

What do consecutive letters A and B in the 4th column of PDB file signify?

What do the consecutive A and B in the 4th column identify in a PDB file downloaded from rcsb.org? The molecule name is 3CZ3 (...
majumderS's user avatar
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Endothermic peak in DSC

I have an endothermic peak, with no mass loss and no change in (organic) crystal structure (monitored by vt-pxrd). What can cause such effect? Also, excluding the options of impurities or instrumental ...
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Why does zircon hate lead? How do these tiny crystals so effectively exclude lead atoms during formation enabling accurate uranium-lead (U-Pb) dating?

Background From the December 29, 2022 NPR article To peer into Earth's deep time, meet a hardy mineral known as the Time Lord: "(Zircons) are really the best markers of Earth's time, or the ...
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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-...
Andi Iacob's user avatar
-1 votes
1 answer
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Is the number of atoms per unit cell for Hexagonal Close-packed (HCP) really 6?

I am questioning whether the conventional N=6 for HCP is accurate. This question is spawned from an image in ZYbooks Material Science and Engineering textbook by Callister and Rethwisch, where they ...
TriGnome's user avatar
4 votes
1 answer
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Role of spin of electron in splitting of orbitals

What will happen if there are electrons with opposite spins present in the orbitals of ligand and metal atom during the splitting of orbitals in crystal field splitting? Magnetic fields of two ...
Chunks  Drunks's user avatar
3 votes
1 answer
3k views

Silicon crystal orientation

I'm confused about how [110] direction is determined for (100), (110) or (111) wafers. I found a book chapter which just confused me even more. From the image below, I understand how [110] is ...
JOHN's user avatar
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0 answers
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Why are crystals of carboxylic acid fluffy

I'm an undergrad student and we recently performed saponification of esters which resulted in the formation of carboxylic acid which we had isolated out of the reaction mixture. After ...
Stu's user avatar
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-2 votes
2 answers
449 views

What is the difference between alloying and doping? [closed]

When compared to doping, how is alloying different? What modifications to the structure are brought about by both of these?
Udeshwari's user avatar
3 votes
1 answer
301 views

Relation between symmetry of a reciprocal vector and lattice planes perpendicular to it

What is the relation the symmetry of a high-symmetry point in the first Brillouin zone and lattice planes perpendicular to it? Are the two symmetries equivalent? I have this question because I want to ...
meTchaikovsky's user avatar
4 votes
1 answer
275 views

Line Entry system like SMILES for metals?

SMILES is not designed for metallic compounds. Is there a similar ASCII line entry notation for metallic compounds, including repeating structure in space, &c.?
Sam's user avatar
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2 votes
1 answer
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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-...
Hendrix13's user avatar
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1 answer
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Is it possible for an appropriately vaporized crystal to have vapor properties in any way related to it's crystal? [closed]

Is it possible for an appropriately vaporized$^{1}$ crystal to have vapor properties in any way$^{2}$ related to it's crystal, or unique to the fact it was a crystal in it's previous phase? The ...
antimony's user avatar
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Database of atomic crystal structure data or images of rocks and minerals?

I am looking for crystal structure images so I can redraw them in a nice form. However, I don't seem to find much searching Google. Perhaps this is a slightly better example (searching for Quartz ...
Lance's user avatar
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8 votes
1 answer
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Does water expand on freezing more than any other known substance?

Several substances expand on freezing. Gallium expands 3.1% and bismuth 3.3%. However, both of these are much less than water which expands 9%. Is there any substance that expands more than 9% on ...
Kevin Kostlan's user avatar
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1 answer
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What are good ways to anticipate co-crystalization of different metal ions?

What rationale (purely theoretical/assumptive, or known by experience / backed by evidence) would you use in an attempt to effectively anticipate which other metal or elemental ions are most likely to ...
Hans's user avatar
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4 votes
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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 ...
andselisk's user avatar
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1 answer
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Are there tools or algorithms to detect organic molecules from 3D crystal structures?

The task I'm thinking of is to detect entire molecules from structures, such as in a crystallographic information file (CIF) or from the XYZ file generated in a molecular dynamics simulation. ...
QGent's user avatar
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-2 votes
1 answer
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What is the structure of hydrated beryllium chloride [closed]

Is there water of crystallization or does water act as ligand? Also Be2+ is smaller than Li 2+ then why Li2+ has only 2 water molecules as ligands
Ritil's user avatar
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6 votes
1 answer
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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 ...
PSR_123's user avatar
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0 answers
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Data for Madelung Constants

Where can I find data for the Madelung constants for various ionic compounds? Specifically, I am looking at silicon tetrachloride, yttrium (III) chloride, zirconium (IV) oxynitrate hydrate, niobium (V)...
Zachary Ireland's user avatar
3 votes
1 answer
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How do other elements fit into a diamond's carbon lattice (e.g. nitrogen in yellow diamonds)

Traditional pure-carbon diamonds have a simple structure (tetrahedral, if I'm not mistaken). But common types of diamonds have other elements within them. For example, yellow diamond has nitrogen in ...
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