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  2. Ethane - Wikipedia

    en.wikipedia.org/wiki/Ethane

    In this form, the positions of the hydrogen atoms are not fixed; the molecules may rotate freely around the long axis. Cooling this ethane below ca. 89.9 K (−183.2 °C; −297.8 °F) changes it to monoclinic metastable ethane II (space group P 21/n). [13] Ethane is only very sparingly soluble in water.

  3. Seesaw molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Seesaw_molecular_geometry

    The seesaw geometry occurs when a molecule has a steric number of 5, with the central atom being bonded to 4 other atoms and 1 lone pair (AX 4 E 1 in AXE notation). An atom bonded to 5 other atoms (and no lone pairs) forms a trigonal bipyramid with two axial and three equatorial positions, but in the seesaw geometry one of the atoms is replaced ...

  4. Molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Molecular_geometry

    This shape is found when there are four bonds all on one central atom, with no extra unshared electron pairs. In accordance with the VSEPR (valence-shell electron pair repulsion theory), the bond angles between the electron bonds are arccos(− ⁠ 1 / 3 ⁠) = 109.47°. For example, methane (CH 4) is a tetrahedral molecule.

  5. Quantum chemistry composite methods - Wikipedia

    en.wikipedia.org/wiki/Quantum_chemistry...

    The G2(+) variant, where the "+" symbol refers to added diffuse functions, better describes anions than conventional G2 theory. The 6-31+G(d) basis set is used in place of the 6-31G(d) basis set for both the initial geometry optimization, as well as the second geometry optimization and frequency calculation.

  6. Isolobal principle - Wikipedia

    en.wikipedia.org/wiki/Isolobal_principle

    Figure 8: Examples of non-basic shapes in the isolobal analogy. The analogy applies to other shapes besides tetrahedral and octahedral geometries. The derivations used in octahedral geometry are valid for most other geometries. The exception is square-planar because square-planar complexes typically abide by the

  7. Pentagonal bipyramidal molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Pentagonal_bipyramidal...

    The pentagonal bipyramid is a case where bond angles surrounding an atom are not identical (see also trigonal bipyramidal molecular geometry). [1] [page needed] This is one of the three common shapes for heptacoordinate transition metal complexes, along with the capped octahedron and the capped trigonal prism. [2] [3] [page needed]

  8. Orbital hybridisation - Wikipedia

    en.wikipedia.org/wiki/Orbital_hybridisation

    Chemist Linus Pauling first developed the hybridisation theory in 1931 to explain the structure of simple molecules such as methane (CH 4) using atomic orbitals. [2] Pauling pointed out that a carbon atom forms four bonds by using one s and three p orbitals, so that "it might be inferred" that a carbon atom would form three bonds at right angles (using p orbitals) and a fourth weaker bond ...

  9. Trigonal prismatic molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Trigonal_prismatic...

    In chemistry, the trigonal prismatic molecular geometry describes the shape of compounds where six atoms, groups of atoms, or ligands are arranged around a central atom, defining the vertices of a triangular prism. The structure commonly occurs for d 0, d 1 and d 2 transition metal complexes with covalently-bound ligands and small charge ...