How do I center the contents of each cell in the middle column? I am approximating it with \phantom, but there's got to be a better way.

  &\Psi&\quad&\phantom{p}\mathrm{"}\phantom{r}&&\quad\frac{\epsilon V}{1+4\pi\epsilon F},\\
  &\Psi&\quad&\phantom{p}\mathrm{"}\phantom{r}&&\quad\frac{(1+4\pi\epsilon F)^2}{\epsilon}.



At its heart the alignat environment is built on TeX's \halign. In that environment you can ignore the formatting specifications for a given column by issuing \omit. Thus writing

\omit\hfill text \hfill

will give you a centered column of text, since the column specification not only included the left/right alignment but also that the meterial is set as mathematics. It is probably best to create a separate command to provide this construction, which may then be used anywhere in an alignat, align or similar enviroment, at the beginning of a cell:

Sample output



\newcommand{\ccol}[1]{\omit\hfill #1\hfill}


  &\Psi&&\ccol{\ditto}&&\frac{\epsilon V}{1+4\pi\epsilon F},\\
  &\Psi&&\ccol{\ditto}&&\frac{(1+4\pi\epsilon F)^2}{\epsilon}.

  E &= mc^2\\
  F &\ccol{is another quantity}\\
  G &= u^2 + v^2 - w^2 + x^2 - y^2 + z^2


Sould you wish to span multiple columns the relevant command is \multispan, e.g. \multispan{3}\hfill text \hfill will place text spread over three columns and centered.

Alternatively, as Harish Kumar suggests you can use array or tabular:

Second sample





  \Psi&\mathrm{\ditto}&\displaystyle\frac{\epsilon V}{1+4\pi\epsilon F},\\
  \Psi&\mathrm{\ditto}&\displaystyle\frac{(1+4\pi\epsilon F)^2}{\epsilon}.

    \( E \)&par&\( \Sigma, \)\\
    \( \Psi \)&\ditto&\( \displaystyle\frac{\epsilon V}{1+4\pi\epsilon F}, \)\\
    \( \Psi \)&\ditto&\( \displaystyle\frac{(1+4\pi\epsilon F)^2}{\epsilon}. \)

However, the default line spacing from alignat is better and you don't need to worry about adjusting the math styles.

  • According to my question here, using this command with alignat breaks numbering. – ominug Sep 14 '15 at 21:18
  • The problem arises when multiple \ccols are used on one line. overleaf.com/read/mvryrbzzgmkw – ominug Sep 14 '15 at 21:57
  • Indeed - it breaks if it is applied to an entry that is not the widest in its column. egreg's answer to your other question address that issue well. – Andrew Swann Sep 15 '15 at 6:35

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