Template talk:Chem2

Additional abbreviations

Please add these fairly common abbreviations:

• Me = 'Methyl group',
• Bu = 'Butyl group',
• Pn = 'Pentyl group',
• Cp = 'Cyclopentadienyl',

Looking at Skeletal formula or other list, it's hard to say which other abbreviations should definitely be added. Many are rare. Many clash with atoms (Ac is actinium, so no acetyl. Pr is praseodymium, so no propyl.) -A876 (talk) 23:08, 3 December 2024 (UTC)

 Done Primefac (talk) 14:40, 25 December 2024 (UTC)

Copernicium named Cp not Cn?

Hey, I'm translating the module into Icelandic and I noticed that Copernicium, element 112 is as Cp and not Cn in the module, see this image:

I'm putting it as Cn in the Icelandic translation since that's the correct one according to the wikipedia page on copernicium, https://en.wikipedia.org/wiki/Copernicium. Would be cool if somebody would fix this on here also, I can't because of the protection. Thanks :) Huldar98 (talk) 00:02, 18 December 2024 (UTC)

Please change (in module:chem2):

	Cp = "Copernicium",

to

	Cn = "Copernicium",

per last comment and copernicium. Christian75 (talk) 02:33, 26 December 2024 (UTC)

 Completed. P.I. Ellsworth , ed. ^{put'er there} 04:49, 26 December 2024 (UTC)

We need to get rid of <br>

Is there a way to get rid of <br> in this template?

1. It interferes with selecting text using three clicks; see the screenshot from Nitrate#Dietary nitrate:

   

2. The copied text becomes

   A source of nitrate in the human diets arises from the consumption of leafy green foods, such as spinach and arugula. NO−
   3 can be present in beetroot juice.

   I'm not sure what would be the preferred form of the text when copied (probably a special syntax like LaTeX in math templates), but "NO−[line break]3" makes no sense.

The same applies to {{chem}}. Jack who built the house (talk) 09:16, 11 April 2025 (UTC)

An issue with hapticity and mu

The μ₂- (\m{2}) should link to bridging ligand with auto=yes.

Besides that, hapticity and mu do not properly link when placed in linking code, like hapticity and every symbol listed in Template:Chem2/doc#All_recognised_symbols_and_codes, and hapticity should link only once:

• {{chem2|(\h{5}Cp)FeCO(\m{2}CO)FeCO(\h{5}Cp)}} → (η⁵-Cp)FeCO(μ₂-CO)FeCO(η⁵-Cp)
• {{chem2|(\h{5}Cp)FeCO(\m{2}CO)FeCO(\h{5}Cp)|auto=yes}} → (η⁵-Cp)FeCO(μ₂-CO)FeCO(η⁵-Cp)
• {{chem2|([[\h{5}]]Cp)FeCO([[\m{2}]]CO)FeCO(\h{5}Cp)}} → ([[\h{5}|η⁵-]]Cp)FeCO([[\m{2}|μ₂-]]CO)FeCO(η⁵-Cp)
• {{chem2|([[Hapticity|\h{5}]]Cp)FeCO([[Bridging ligand|\m{2}]]CO)FeCO(\h{5}Cp)}} → (η⁵-Cp)FeCO(μ₂-CO)FeCO(η⁵-Cp)

–LaundryPizza03 (dc̄) 06:46, 5 December 2025 (UTC)

Fractions

There's a bug/feature that causes fractional coefficients to be displayed improperly. For example, this was in Bombardier beetle:

H₂O₂(aq) → H₂O(l) + 1/₂O₂(g)

By splitting it into two chem2 templates and a frac2, I changed that line to:

H₂O₂(aq) → H₂O(l) + ⁠1/2⁠O₂(g)

I wanted to get some feedback before I bother to fix other pages. AndyBloch (talk) 03:56, 10 January 2026 (UTC)

Seconding this. Is there a way to do a "Feature request"? I'd like native support for fractions to be added in here without having to split things or use hacks like ^{3}/_{2}. ~2026-34298-51 (talk) 19:21, 10 June 2026 (UTC)

@AndyBloch: Not sure if you're still concerned with this, but an alternative is to just multiply out the fraction, as another editor already did on Bombardier beetle a while after your edit. Fractional stoichiometric numbers are fictitious. They're a useful fiction when quantifying the, eg, enthalpy change for reaction with respect to a particular product on a per mole basis, but otherwise don't have much reason to be used. (Surprisingly, MOS:CHEM doesn't seem to address when to use/avoid fractional stoichiometric numbers; it probably should.)

That said, some articles do have a good reason include enthalpy information so I actually would support adding a native method for formatting fractions within {{chem2}}. Ideally it would use familiar formatting like \frac{}{} or \f{}{}.

If anyone passing through is good with coding modules, I'd encourage them to draft something at Module:Chem2/sandbox. – Scyrme (talk/solidarity) 00:00, 22 September 2026 (UTC)

Discussion at Wikipedia talk:Manual of Style/Accessibility § MOS still encourages chemistry articles to indent with colons

 You are invited to join the discussion at Wikipedia talk:Manual of Style/Accessibility § MOS still encourages chemistry articles to indent with colons.

The guidelines at MOS:CHEMINDENT are presently inconsistent with the rest of WP:MOS. The discussion concerns changes (most likely to {{chem}}/{{chem2}} and {{pad}}) to provide alternatives which would allow the guidelines to be made consistent. Nothing has been decided yet and the input of editors with technical knowledge of how this template works would be welcome. – Scyrme (talk/solidarity) 19:02, 28 July 2026 (UTC)

Enthalpies

Is this template also intended to encompass the inclusion of enthalpy information? It seems like technically it can, but it requires getting creative because the template can't handle things like \Delta H^{\circ} so you have to use workarounds like ΔH°.

If it's not intended, what's the appropriate method for appending this information so that the HTML/formatting is consistent? Looking articles for examples hasn't been helpful, since the example I've found are like Haber process, which uses <math>...</math> contrary to the recommendations of MOS:CHEM. I'm struggling to find a MOS-compliant example. – Scyrme (talk/solidarity) 22:52, 21 September 2026 (UTC)