/// <summary>
/// Removes rings which do not have all sp2/planar3 aromatic atoms.
/// and also gets rid of rings that have more than 8 atoms in them.
/// </summary>
/// <param name="m">The <see cref="IAtomContainer"/> from which we want to remove rings</param>
/// <returns>The set of reduced rings</returns>
private static IRingSet RemoveExtraRings(IAtomContainer m)
{
IRingSet rs = Cycles.FindSSSR(m).ToRingSet();
//remove rings which don't have all aromatic atoms (according to hybridization set by lower case symbols in smiles):
var rToRemove = new List <int>();
for (int i = 0; i < rs.Count; i++)
{
if (rs[i].Atoms.Count > 8)
{
rToRemove.Add(i);
}
else
{
foreach (var a in rs[i].Atoms)
{
Hybridization h = a.Hybridization;
if (h.IsUnset() || !(h == Hybridization.SP2 || h == Hybridization.Planar3))
{
rToRemove.Add(i);
break;
}
}
}
}
rToRemove.Reverse();
foreach (var ri in rToRemove)
{
rs.RemoveAt(ri);
}
return(rs);
}
