Hacker News Reader

Comment by SAI_Peregrinus | Hacker News Reader

Our bodies can synthesize several inorganic compounds, and other organisms can synthesize even more. There are biological sources of $H_{2}O$, $NH_{4}^{+}$, $NO$, $HCO_{3}^{−}$, $HPO_{4}^{2−}$, and (traditionally considered inorganic despite having carbon) $CO_{2}$. Iodine is an element, not a compound, and can only be synthesized through nuclear processes, not chemical ones.

View on HN

I feel your use of TeX (or whatever that notation is precisely ...) is far too clear.

Possibly use InChI instead, so instead of "$HPO_{4}^{2−}$", use "InChI=1S/H3O4P/c1-5(2,3)4/h(H3,1,2,3,4)/p-2". Or, more concisely, just use the key, which is "NBIIXXVUZAFLBC-UHFFFAOYSA-L". :)

(from : https://www.ebi.ac.uk/chebi/searchId.do?chebiId=43474)

Or just unicode. Standard digraphs ftw (xcompose, wincompose...). It's even typed in the same way (_4 ^+ etc) - and maybe there's tex tools that output unicode these days where possible?

H₂O, NH₄⁺, NO, HCO₃⁻, HPO₄²⁻

Yes, that's pretty good ... but - the charges on [NH4]+, [HCO3]-, and [HPO4]2- should be above the subscripts on their last atoms. Minor point really.

true, true... I wonder if that's even possible to do in unicode. maybe some combining char thing. I certainly wouldn't be able to type a digraph of it from memory if it is. But, I feel it's still more readable this way

Or Hacker News could finally add support for LaTeX and markdown...

The definition I remember from my chemistry class is that organic compounds are those having at least one C-H bond.

It's a reasonable definition, especially when classifying biochemicals, but there are always edge cases.

For example : https://en.wikipedia.org/wiki/Carborane that definitely do have C-H bonds but are mostly B-B, B-C, B-H.

What is this kind of notation from/based on? e.g $H_{2}O$

Looks like LaTeX syntax.

LaTeX would be $H_{2}O$ – or, more likely, \ce{H2O} or \ch{H2O}.

That's TeX. Every time Donald Knuth gets distracted from writing The Art of Computer Programming, he makes another piece of load-bearing infrastructure. (TeX came about because the second edition of Volume 1 didn't look as nice as the first edition.)

Reply on news.ycombinator.com