NAME

       Chemistry::OpenSMILES::Aromaticity - Aromaticity handling routines

DESCRIPTION

       Chemistry::OpenSMILES::Aromaticity encodes some aromaticity handling subroutines for aromatisation and
       kekulisation. Both implementations are experimental, handle only some specific cases and are neither
       stable nor bug-free, thus should be used with caution.

METHODS

       aromatise( $moiety )
           Mark electron cycles as aromatic.

       kekulise( $moiety, $order_sub )
           Find  nonfused  even-length  aromatic  cycles  consisting  only  of  B, C, N, P, S and mark them with
           alternating single and double bonds.  Subroutine as well accepts  an  optional  subroutine  reference
           $order_sub,  providing  external  order  for  atoms.   This  is needed to stabilise the algorithm, as
           otherwise the outcomes of bond assignment may turn out different.  $order_sub is called with an  atom
           as  $_[0]  and  is  expected  to return a value providing a distinct order indication for every atom.
           These can be any scalar values, comparable using Perl's "cmp" operator.  If $order_sub is not  given,
           initial atom order in input is consulted.

       electron_cycles( $moiety )
           Find    electron    cycles    according    to    "Finding    Electron    Cycles"    algorithm    from
           <https://depth-first.com/articles/2021/06/30/writing-aromatic-smiles/>.   Use   with   caution:   the
           implementation is experimental.

perl v5.40.0                                       2025-02-14             Chemistry::Open...ES::Aromaticity(3pm)