chemcoord.Zmat.iupacify

Zmat.iupacify()

Give the IUPAC conform representation.

Mathematically speaking the angles in a zmatrix are representations of an equivalence class. We will denote an equivalence relation with \(\sim\) and use \(\alpha\) for an angle and \(\delta\) for a dihedral angle. Then the following equations hold true.

\[\begin{split}(\alpha, \delta) &\sim (-\alpha, \delta + \pi) \\ \alpha &\sim \alpha \mod 2\pi \\ \delta &\sim \delta \mod 2\pi\end{split}\]

IUPAC defines a designated representation of these equivalence classes, by asserting:

\[\begin{split}0 \leq &\alpha \leq \pi \\ -\pi \leq &\delta \leq \pi\end{split}\]

Parameters:None – Returns:Zmatrix with accordingly changed angles and dihedrals. Return type:Zmat