# Per mille symbol in classicthesis style

I need the per mille (\textperthousand) symbol in math mode and text in a classicthesis style document. Instead, in the PDF, I get a percent symbol followed by a small, black square.

For example, this LaTeX code

For example, for carbon-13,
$\delta^{13}{\textrm C} = \left( \frac{ \left( \frac{^{13}\textrm C}{^{12}\textrm C} \right) _{sample}- \left(\frac{^{13}\textrm C}{^{12}\textrm C}\right)_{standard}}% {\left(\frac{^{13}\textrm C}{^{12}\textrm C}\right)_{standard}}% \right) \times 1000 \qquad\textperthousand$
This value, represented by a delta ($\delta$) prefixing the mass number and symbol for the element, is in parts per thousand or \emph{permil} (\textperthousand).


produces correct output when typeset using PDFLaTeX or XeLaTeX using the article style but not when typeset using PDFLaTeX with the classicthesis style.

Is there something I can do to obtain the correct symbol?

• \usepackage{wasysym} provides \permil which gives you the same symbol. Does that help? – Emiel Jul 11 '13 at 13:55
• Welcome to TeX.SX! Rather than a classicthesis problem it's a font problem. The style uses the mathpazo package that sets the main font to Palatino. Try loading also the textcomp package. Note also that you should say \text{\textperthousand}, in order to avoid warning messages. – egreg Jul 11 '13 at 13:55

The \textperthousand command is available both with the T1 encoding (used by classicthesis) and the TS1 encoding.

However, the Palatino font loaded via the mathpazo package by classicthesis hasn't the required glyph: in the T1 encoding \textperthousand is built by adding a small zero next to % and the small zero is missing (a black square is used to show this).

However the Palatino text companion font has the glyph \textperthousand, so all you need to do is to load textcomp: add

\usepackage{textcomp}


Note that \textperthousand is not legal in math mode and produces a warning. You can avoid it by using

\mbox{\textperthousand}


or, better, by loading also amsmath and using

\text{\textperthousand}


You may want to define a variant command that works both in text and math mode:

\usepackage{textcomp}
\usepackage{amsmath}
\DeclareRobustCommand{\perthousand}{%
\ifmmode
\text{\textperthousand}%
\else
\textperthousand
\fi}