# Longtable error with many columns

I am using using XeTeX, Version 3.1415926-2.4-0.9998 (TeX Live 2012/W32TeX). I need to have a prosodic map for a verse showing heavy and light syllables, like that shown on page 2 of this link. The example in the link uses macron and breve for heavy and light syllables, I use numbers 2 and 1 instead. I use longtable since the poem is quite long and the prosodic map will run into several pages.

The following does not compile

\documentclass[twoside]{book}
\usepackage{longtable}
\usepackage{array}
\newcolumntype{C}[1]{>{\centering}m{#1}}
\usepackage[top=2.25cm,left=1.25cm,bottom=1.5cm,right=1.25cm,paperwidth=120mm,paperheight=200mm]{geometry}
\begin{document}
\fontsize{9}{11.5}\selectfont
\begin{center}
\begin{longtable}{|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}|@{}C{6mm}@{}}
1 & 1 & 1 & 1 & 1 & 1 & 1 & 1 & 1 & 1 & 1 & 1 & 2 & 2 \\
tu & ma & ma & ma & pri & ya & bha & ra & ta & hi & sa & ma & bha & i \\
\end{longtable}
\end{center}
\end{document}


I get the error

Extra alignment tab has been changed to \cr.

• This looks like there is at least one & in your table. Count the numbers of column specifiers and the & and either add one column or remove the overhanging & ;'-) – user31729 Apr 21 '15 at 5:08
• There are fourteen columns and exactly 13 &s in each line, which is what is expected. So the error is not that trivial.What is surprising is, if I comment any of the table rows, the file compiles successfully. I also tried this in Linux on pdfeTeX 3.141592-1.21a-2.2 (Web2C 7.5.4) and get the same result. – user22209 Apr 21 '15 at 5:52

You have to add \arrabackslash in

\newcolumntype{C}[1]{>{\centering\arraybackslash}m{#1}}


so that the meaning of \\ is not messed up. Further, for such repeated columns, you may use

{|*{14}{@{}C{6mm}@{}|}}


\documentclass[twoside]{book}
\usepackage{longtable}
\usepackage{array}
\newcolumntype{C}[1]{>{\centering\arraybackslash}m{#1}}
\usepackage[top=2.25cm,left=1.25cm,bottom=1.5cm,right=1.25cm,paperwidth=120mm,paperheight=200mm]{geometry}
\begin{document}
\fontsize{9}{11.5}\selectfont
\begin{center}
\begin{longtable}{|*{14}{@{}C{6mm}@{}|}}
1  & 1  & 1  & 1  & 1   & 1  & 1   & 1  & 1  & 1  & 1  & 1  & 2   & 2 \\
tu & ma & ma & ma & pri & ya & bha & ra & ta & hi & sa & ma & bha & i
\end{longtable}
\end{center}
\end{document}