# Horizontal alignment of content in two different tabular rows

I have a tabular table with all elements left-justified. Here is the MWE code followed by the output:

\documentclass{article}

\begin{document}

\begin{table}
\begin{tabular}{lll}
\toprule
& $\alpha$ & $\beta$\\
\midrule
atomic $\text{C}$ & 1.1 & 2.2\\
($\text{C}_a$) & & \\ \addlinespace
polymeric $\text{C}$ & 3.3 & 4.4\\
($\text{C}_p$) & & \\
\bottomrule
\end{tabular}
\end{table}

\end{document}


• I would like to align the C in C_a with the the C in "atomic C".
• I would also like to align the C in C_p with the C in "polymeric C".

In other words, indent C_a and C_b so that they align with the C immediately above.

Is this possible in a relatively simple way?

(In actuality, I am using the chemmacros package to typeset the C's (e.g., \ch{C}), but to keep things simple in my MWE, I used \text. I think that the answer to this question, if one exists, will probably be independent of whether I use \ch or \text.)

• Please make your example code compilable by adding the missing packages. Regarding your use of \text instead of \ch in your MWE: To be honest, I don't think, using \text for simplicity really helps here. For \text you need to load amsmath, for \ch, you also just need one package, so I can't realls see the simplicity here. – leandriis Oct 19 at 18:25

Here's a solution that employs the \mathllap macro of the mathtools package, which is a superset of the amsmath package, to facilitate the alignment of the \ch{C} elements.

\documentclass{article}
\usepackage{chemmacros,booktabs,mathtools}
\newcommand\myarray[2]{%
$\begin{array}[t]{@{}l@{}} #1 \\ \mathllap{(}#2) \end{array}$}
\begin{document}

\begin{table}
\centering
\begin{tabular}{@{}lcc@{}}
\toprule
& $\alpha$ & $\beta$\\
\midrule
atomic \myarray{\ch{C}}{\ch{C}_a} & 1.1 & 2.2\\
polymeric \myarray{\ch{C}}{\ch{C}_p} & 3.3 & 4.4\\
\bottomrule
\end{tabular}
\end{table}

\end{document}


Here is a method using \widthof from the calc package in order to measure the required indentation:

\documentclass{article}
\usepackage{booktabs}
\usepackage{chemmacros}
\usepackage{calc}

\newlength{\mylengthatomic}
\setlength{\mylengthatomic}{\widthof{atomic}-\widthof{(}}
\newlength{\mylengthpolymeric}
\setlength{\mylengthpolymeric}{\widthof{polymeric}-\widthof{(}}
\begin{document}

\begin{table}
\begin{tabular}{lll}
\toprule
& $\alpha$ & $\beta$\\
\midrule
atomic \ch{C}  & 1.1 & 2.2\\
\hspace{\mylengthatomic} (\ch{C_a}) & & \\ \addlinespace
polymeric \ch{C} & 3.3 & 4.4\\
\hspace{\mylengthpolymeric} (\ch{C_p}) & & \\
\bottomrule
\end{tabular}
\end{table}

\end{document}


The second example uses nested tabulars for the alignment:

\documentclass{article}
\usepackage{booktabs}
\usepackage{chemmacros}

\begin{table}
\begin{tabular}{lll}
\toprule
& $\alpha$ & $\beta$\\
\midrule
\setlength{\tabcolsep}{0pt}\begin{tabular}[t]{ll} atomic & \phantom{(}\ch{C} \\ & (\ch{C_a})\end{tabular}  & 1.1 & 2.2\\ \addlinespace
\setlength{\tabcolsep}{0pt}\begin{tabular}[t]{ll} polymeric & \phantom{(}\ch{C} \\ & (\ch{C_p})\end{tabular} & 3.3 & 4.4\\
\bottomrule
\end{tabular}
\end{table}

\end{document}