[texhax] units, chemistry and mhchem

[Gordon Haverland]

On December 29, 2011, Simmie, John wrote:
> Chemists use a superscript bullet to denote an unpaired
> electron or the construct \.{C} or $\dot{C}H_3$ MHCHEM cannot
> do this ... the author of the package was reluctant to take my
> word that that is what we chemists use.
> 
> Also we use two superscript dots over the element symbol  to
> denote a carbene, thus \"{C}

Most of the chemistry I've been writing of late is of the nuclear 
variety (I come from materials science and engineering).  I don't 
think I've ever had to note unpaired electrons in a chemical 
formula.  The NIST recommendations for nuclear metastable states 
are different than I commonly have commonly seen: Sc-46m I 
normally see as \isotope[46m]{Sc}.  The version of isotope I have 
been using seems old, maybe the new one corresponds with the NIST 
document?

I suppose our (MSE) oddball unit will still come out kind of 
screwy with siunitx (\SI{15}{MPa.m\tothe{0.5}})?  It isn't 
mentioned in the NIST document.

In the mhchem documentation, I actually like the examples where 
serif and sans serif are mixed.

Taking John Simmie's example of a dangling bond for inspiration, I 
would disagree with the NIST recommendation on nuclear metastable 
states.  For example, if we are working with 

 \ce{^{180}Ta^m5+}

it looks wrong to have the m after the elemental symbol to me.  
I've no idea if that typesets correctly.  What looks better using 
mhchem (to me) is

  \ce{^{180m}Ta^5+}


But this has been an enlightening topic.

-- 
Gord