What is meant by antifluorite structure?
Antifluorite is a mineral with a crystal structure identical with that of fluorite but with the positions of the cations and anions reversed (Figure 6.11D. The same crystal structure is found in numerous ionic compounds with formula AB2, such as ceria (CeO2), zirconia (cubic ZrO2), uranium dioxide (UO2).
What is the coordination number of antifluorite structure?
The antifluorite structure is the opposite arrangement, with anions in the fcc array with coordination number 8 and cations in the tetrahedral holes with coordination number 4.
What is the structure of CaF2?
Calcium fluoride
| Identifiers | |
|---|---|
| Crystal structure | cubic crystal system, cF12 |
| Space group | Fm3m, #225 |
| Lattice constant | a = 5.451 Å, b = 5.451 Å, c = 5.451 Å α = 90°, β = 90°, γ = 90° |
| Coordination geometry | Ca, 8, cubic F, 4, tetrahedral |
What is ax type crystal structure?
There are five main AX structure types: rock salt, CsCl, NiAs, sphalerite and wurtzite, each of which is found in a large number of compounds.
Which of the following compounds have an antifluorite structure?
Some common substances with antifluorite structure are Na2O,Li2O,Rb2OandRb2S.
What is the coordination number of the Ti4+ ion in terms of surrounding O2 ions?
The O2− ions are surrounded by three Ti4+ ions. The coordination of the titanium (IV) cation is 6, which is twice the coordination number of the oxide anion, which is 3.
What is the coordination number of a Ti4+ site and the O2 site in rutile?
Rutile structure (TiO2) The hexagonal closed package is strongly distorted. Regarding to the model, in this structure the cations occupy only half of the octahedral holes in an ordered manner. Each Ti4+ atom is surrounded by six 02- atoms and each O2- atom is surrounded by three Ti4+ ions. Coordination number: (6:3).
What is CaF2?
Calcium fluoride (CaF2) is the primary source of fluorine worldwide. It occurs as the mineral fluorite or fluorspar.
Is CaF2 linear or bent?
CaF2 is neither linear nor bent because it is an ionic compound and ionic bond is non directional.
What is the difference between atomic structure and crystal structure?
(i) Atomic structure relates to the number of protons and neutrons in the nucleus of an atom, as well as the number and probability distributions of the constituent electrons. On the other hand, crystal structure pertains to the arrangement of atoms in the crystalline solid material.
What is NaCl crystal structure?
NaCl is a crystal structure with a face centered cubic Bravais lattice and two atoms in the basis. One Na atom comes from the 8 corners and 3 from the six faces. One Cl atom is in the center and 3 come from the twelve edges. The Bravais lattice is fcc.