stibole convert to sulphur?

[ctc-er]

---

Screenshots
When I use the capital letter 'Sb' and 'Se', it is expected, but the lowercase letter' sb' becomes sulfur, which is different from 'Se'

Configuration (please complete the following information):

• RDKit version: 2022.9.5
• OS: Windows
• Python version (if relevant): 3.8.8
• Are you using conda? yes
• If you are using conda, which channel did you install the rdkit from? pip install

Additional context
Add any other context about the problem here.

[bp-kelley]

Definitely a bug

>>> Chem.MolToSmiles(Chem.MolFromSmiles("[Sb]"))
'[Sb]'
>>> Chem.MolToSmiles(Chem.MolFromSmarts("[sb]"))
's'
>>> m = Chem.MolFromSmarts("[sb]")
>>> m.Debug()
Atoms:
        0 16 S chg: 0  deg: 0 exp: N/A imp: N/A hyb:  arom?: 1 query: AtomAnd
Bonds:

[bp-kelley]

Seems to be endemic:

>>> m = Chem.MolFromSmarts("[nb][cb][pb]")
>>> Chem.MolToSmiles(m)
'ncp'

[bp-kelley]

The smarts parser isn't allowing "Sb" to be aromatic so it is converting the query into "sulphur & boron" which won't match anything. The fix is pretty easy, I'm passing it by @greglandrum

[greglandrum]

I agree that this is confusing, but it's not a bug: the RDKit doesn't support aromatic Sb in either SMILES or SMARTS, so (as @bp-kelley says), sb is interpreted as s&b in SMARTS.
In SMILES it's just an error

We should think about generating a warning in the SMARTS parser if there are two atom tokens directly following each other.