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  2. Bond length - Wikipedia

    en.wikipedia.org/wiki/Bond_length

    It is generally considered the average length for a carbon–carbon single bond, but is also the largest bond length that exists for ordinary carbon covalent bonds. Since one atomic unit of length (i.e., a Bohr radius) is 52.9177 pm, the C–C bond length is 2.91 atomic units, or approximately three Bohr radii long.

  3. Hydrogen bond - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_bond

    Consequently, hydrogen bonds between or within solute molecules dissolved in water are almost always unfavorable relative to hydrogen bonds between water and the donors and acceptors for hydrogen bonds on those solutes. [44] Hydrogen bonds between water molecules have an average lifetime of 10 −11 seconds, or 10 picoseconds. [45]

  4. 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.

  5. Z-matrix (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Z-matrix_(chemistry)

    In chemistry, the Z-matrix is a way to represent a system built of atoms.A Z-matrix is also known as an internal coordinate representation.It provides a description of each atom in a molecule in terms of its atomic number, bond length, bond angle, and dihedral angle, the so-called internal coordinates, [1] [2] although it is not always the case that a Z-matrix will give information regarding ...

  6. Protein contact map - Wikipedia

    en.wikipedia.org/wiki/Protein_contact_map

    Preliminary binding of a ligand near to the entrance breaks hydrogen bonds S212-E474, S207-H172 in the open form of CYP2B4 and hydrogen bonds E218-A102, Q215-L51 are formed that fix the entrance in the closed form as the HB plot reveals. The second step is the transfer of the first electron from NADPH via an electron transfer chain. For the ...

  7. Covalent radius - Wikipedia

    en.wikipedia.org/wiki/Covalent_radius

    The covalent radius, r cov, is a measure of the size of an atom that forms part of one covalent bond. It is usually measured either in picometres (pm) or angstroms (Å), with 1 Å = 100 pm. In principle, the sum of the two covalent radii should equal the covalent bond length between two atoms, R(AB) = r(A) + r(B).

  8. 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.

  9. C–H···O interaction - Wikipedia

    en.wikipedia.org/wiki/C–H···O_interaction

    The directionality of a C–H···O interaction is usually defined by the angle α between the С, Н and О atoms, and the distance d between the O and C atoms. In a С–Н···О interaction, the angle α is in the range between 90 and 180°, and the distance d is usually smaller than 3.2 Å. [5] Bond strength is less than 1 kcal/mol.