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  2. Bond valence method - Wikipedia

    en.wikipedia.org/wiki/Bond_valence_method

    If the structure of a compound is known, the empirical bond valence - bond length correlation of Eq. 2 can be used to estimate the bond valences from their observed bond lengths. Eq. 1 can then be used to check that the structure is chemically valid; any deviation between the atomic valence and the bond valence sum needs to be accounted for.

  3. Lewis structure - Wikipedia

    en.wikipedia.org/wiki/Lewis_structure

    Assume single bonds and use the actual bond number to calculate lone pairs. Expanded Octet (only occurs for elements in Groups 3-8) Bond calculation will provide too few bonds for the number of atoms in the molecule. Assume single bonds, use the minimum number of bonds necessary to create the molecule.

  4. Structural formula - Wikipedia

    en.wikipedia.org/wiki/Structural_formula

    Lewis structure is best used to calculate formal charges or how atoms bond to each other as both electrons and bonds are shown. Lewis structures give an idea of the molecular and electronic geometry which varies based on the presence of bonds and lone pairs and through this one could determine the bond angles and hybridization as well.

  5. Skeletal formula - Wikipedia

    en.wikipedia.org/wiki/Skeletal_formula

    The skeletal formula of the antidepressant drug escitalopram, featuring skeletal representations of heteroatoms, a triple bond, phenyl groups and stereochemistry. The skeletal formula, line-angle formula, bond-line formula or shorthand formula of an organic compound is a type of molecular structural formula that serves as a shorthand representation of a molecule's bonding and some details of ...

  6. Molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Molecular_geometry

    Molecular geometries can be specified in terms of 'bond lengths', 'bond angles' and 'torsional angles'. The bond length is defined to be the average distance between the nuclei of two atoms bonded together in any given molecule. A bond angle is the angle formed between three atoms across at least two bonds.

  7. Tetrahedral molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Tetrahedral_molecular_geometry

    In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron.The bond angles are arccos(− ⁠ 1 / 3 ⁠) = 109.4712206...° ≈ 109.5° when all four substituents are the same, as in methane (CH 4) [1] [2] as well as its heavier analogues.

  8. WIEN2k - Wikipedia

    en.wikipedia.org/wiki/WIEN2k

    WIEN2k uses density functional theory to calculate the electronic structure of a solid. It is based on the most accurate scheme for the calculation of the bond structure-the full potential energy (linear) augmented plane wave ((L) APW) + local orbit (lo) method. WIEN2k uses an all-electronic solution, including relativistic terms.

  9. Degree of unsaturation - Wikipedia

    en.wikipedia.org/wiki/Degree_of_unsaturation

    For hydrocarbons, the DBE (or IHD) tells us the number of rings and/or extra bonds in a non-saturated structure, which equals the number of hydrogen pairs that are required to make the structure saturated, simply because joining two elements to form a ring or adding one extra bond (e.g., a single bond changed to a double bond) in a structure reduces the need for two H's.