enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Square antiprismatic molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Square_antiprismatic...

    Square prismatic geometry (D 4h) is much less common compared to the square antiprism.An example of a molecular species with square prismatic geometry (a slightly flattened cube) is octafluoroprotactinate(V), [PaF 8] 3–, as found in its sodium salt, Na 3 PaF 8. [6]

  3. Square pyramidal molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Square_pyramidal_molecular...

    The point group symmetry involved is of type C 4v. The geometry is common for certain main group compounds that have a stereochemically-active lone pair, as described by VSEPR theory. Certain compounds crystallize in both the trigonal bipyramidal and the square pyramidal structures, notably [Ni(CN) 5] 3−. [1]

  4. Dodecahedral molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Dodecahedral_molecular...

    In chemistry, the dodecahedral molecular geometry describes the shape of compounds where eight atoms or groups of atoms or ligands are arranged around a central atom defining the vertices of a snub disphenoid (also known as a trigonal dodecahedron).

  5. Molecular symmetry - Wikipedia

    en.wikipedia.org/wiki/Molecular_symmetry

    Symmetry elements of formaldehyde. C 2 is a two-fold rotation axis. σ v and σ v ' are two non-equivalent reflection planes.. In chemistry, molecular symmetry describes the symmetry present in molecules and the classification of these molecules according to their symmetry.

  6. Crystallographic point group - Wikipedia

    en.wikipedia.org/wiki/Crystallographic_point_group

    In crystallography, a crystallographic point group is a three dimensional point group whose symmetry operations are compatible with a three dimensional crystallographic lattice. According to the crystallographic restriction it may only contain one-, two-, three-, four- and sixfold rotations or rotoinversions. This reduces the number of ...

  7. Polyhedral skeletal electron pair theory - Wikipedia

    en.wikipedia.org/wiki/Polyhedral_skeletal...

    To predict the structure of an arachno cluster, the closo polyhedron with n + 2 vertices is used as the starting point, and the n + 1 vertex nido complex is generated by following the rule above; a second vertex adjacent to the first is removed if the cluster is composed of mostly small atoms, a second vertex not adjacent to the first is ...

  8. Isomorphism (crystallography) - Wikipedia

    en.wikipedia.org/wiki/Isomorphism_(crystallography)

    Forsterite. In chemistry, isomorphism has meanings both at the level of crystallography and at a molecular level. In crystallography, crystals are isomorphous if they have identical symmetry and if the atomic positions can be described with a set of parameters (unit cell dimensions and fractional coordinates) whose numerical values differ only slightly.

  9. Cation-anion radius ratio - Wikipedia

    en.wikipedia.org/wiki/Cation-anion_radius_ratio

    In condensed matter physics and inorganic chemistry, the cation-anion radius ratio can be used to predict the crystal structure of an ionic compound based on the relative size of its atoms. It is defined as the ratio of the ionic radius of the positively charged cation to the ionic radius of the negatively charged anion in a cation-anion compound.