Is there a standard symbol for molar density, i.e. $n/V$, where $n$ is the total number of moles of every species in a system?
I realise that there is standard term "molar volume", which is the reciprocal of what I'm asking for, but my equations are going to look pretty silly with $1/V_m$ written everywhere. As a simple example, I want to say that if my system consists of a mixture of $\ce{A}$ and $\ce{B}$ with the reaction $\ce{A <-> B}$, the total concentration of $\ce{A}$ and $\ce{B}$ will be constant and we can write $$ \ce{[B]} = c - \ce{[A]}, $$ where $c$ is the thing I'm looking for the symbol for.
I didn't find "molar density" in the IUPAC green book, but I don't know my way around it very well, and if it has a different name it might be hiding somewhere I didn't think to look.