/// <summary>
/// <pre>
/// -C#N
/// -[N+]#[C-]
/// -C=[N+]=N
/// -N=[N+]=N
/// </pre>
/// </summary>
internal static bool IsColinear(IAtom atom, IEnumerable <IBond> bonds)
{
if (PeriodicTable.IsMetal(atom.AtomicNumber))
{
return(bonds.Count() == 2);
}
int numSgl = atom.ImplicitHydrogenCount ?? 0;
int numDbl = 0;
int numTpl = 0;
int count = 0;
foreach (var bond in bonds)
{
++count;
switch (bond.Order.Numeric())
{
case 1:
numSgl++;
break;
case 2:
numDbl++;
break;
case 3:
numTpl++;
break;
case 4:
return(true);
default:
return(false);
}
}
if (count != 2)
{
return(false);
}
switch (atom.AtomicNumber)
{
case 6:
case 7:
case 14:
case 32:
if (numTpl == 1 && numSgl == 1)
{
return(true);
}
if (numDbl == 2 && numSgl == 0)
{
return(true);
}
break;
}
return(false);
}
