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  2. Spinel group - Wikipedia

    en.wikipedia.org/wiki/Spinel_group

    Inverse spinel structures have a different cation distribution in that all of the A cations and half of the B cations occupy octahedral sites, while the other half of the B cations occupy tetrahedral sites. An example of an inverse spinel is Fe 3 O 4, if the Fe 2+ (A 2+) ions are d 6 high-spin and the Fe 3+ (B 3+) ions are d 5 high-spin.

  3. Pauling's rules - Wikipedia

    en.wikipedia.org/wiki/Pauling's_rules

    For typical ionic solids, the cations are smaller than the anions, and each cation is surrounded by coordinated anions which form a polyhedron.The sum of the ionic radii determines the cation-anion distance, while the cation-anion radius ratio + / (or /) determines the coordination number (C.N.) of the cation, as well as the shape of the coordinated polyhedron of anions.

  4. Filipstadite - Wikipedia

    en.wikipedia.org/wiki/Filipstadite

    Filipstadite is a very rare mineral [4] of the spinel group, with the formula (Mn,Mg)(Sb 5+ 0.5 Fe 3 + 0.5)O 4. [5] It is isometric, [3] although it was previously thought to be orthorhombic. When compared to a typical spinel, both the octahedral and tetrahedral sites are split due to cation ordering. [3] Filipstadite is chemically close to ...

  5. Hercynite - Wikipedia

    en.wikipedia.org/wiki/Hercynite

    Hercynite is a spinel of regular symmetry and normal cation distribution, but some disorder occurs in its structure. It consists of ferrous (Fe 2+) ions and aluminium ions (Al 3+); however some ferric ions (Fe 3+) may be located in the structure of hercynite. [5] Melting point of this mineral is inbetween 1,692–1,767 °C (3,078–3,213 °F). [6]

  6. Ceylonite - Wikipedia

    en.wikipedia.org/wiki/Ceylonite

    The mineral ceylonite has the chemical composition of (Mg, Fe 2+) Al 2 O 4, putting it into a group of minerals known as the spinel group, or the oxide spinels. The oxide spinels have a formula of the model [A][B] 2 O 4; where [A] is commonly Fe 2+, Mg 2+, or Mn 2+, and [B] is Fe 3+, Al 3+, or Cr 3+. It is an iron-rich variety of the spinel ...

  7. Purchase rates for Wednesday, December 4, 2024 - AOL

    www.aol.com/finance/mortgage-and-refinance-rates...

    See today's average mortgage rates for a 30-year fixed mortgage, 15-year fixed, jumbo loans, refinance rates and more — including up-to-date rate news.

  8. 20 iconic Christmas movie foods ranked according to nutrition

    www.aol.com/20-iconic-christmas-movie-foods...

    The list above shows the healthiest Christmas movie eats and treats based on their overall calorie, protein, fiber, sugar, and fat content. But which ones really pack in the calories, and which ...

  9. Crystal field theory - Wikipedia

    en.wikipedia.org/wiki/Crystal_field_theory

    According to crystal field theory, the interaction between a transition metal and ligands arises from the attraction between the positively charged metal cation and the negative charge on the non-bonding electrons of the ligand.