# Radical spacing/kerning on script-r symbol

I have followed the directions on this page regarding how to make a script-r using the calligra font package. I'm decently pleased with how the script-r looks, but the kerning with radicals leaves a little to be desired, in my opinion.

As you can see, the squared radical is positioned a bit far left of where I might expect it to be as compared to the regular "r." I would think that shifting it right by a \, might do it, but being able to play with the spacing would be good.

How can I move the spacing of radicals for this \sr definition? MWE below.

\documentclass[letterpage,12pt]{book}

\usepackage{amsmath,amsthm,amssymb}
\DeclareMathSizes{12}{12}{6}{6}

% Declares the font
\usepackage{calligra}
\DeclareMathAlphabet{\mathcalligra}{T1}{calligra}{m}{n} \DeclareFontShape{T1}{calligra}{m}{n}{<->s*[2.2]callig15}{}
% Makes '\sr' make a script r
\newcommand{\sr}{\ensuremath{\mathcalligra{r}}}

\begin{document}

\begin{equation*}
\mathrm{R}^2 = r^2 + \sr^2 - 2r \sr \cos\omega
\end{equation*}

\end{document}


Reserving a math group for a single letter is a waste; you can do it more simply with the bonus that you can also add spacing around it.

\documentclass[letterpaper,12pt]{book}

\usepackage{amsmath,amsthm,amssymb}

%\DeclareMathSizes{12}{12}{6}{6} % Are you sure? I wouldn't be. ;-)

\DeclareFontFamily{T1}{calligra}{}
\DeclareFontShape{T1}{calligra}{m}{n}{<->s*[2.2]callig15}{}

\DeclareRobustCommand{\sr}{%
\mspace{-2mu}%
\text{\usefont{T1}{calligra}{m}{n}r\/}%
\mspace{2mu}%
}

\begin{document}

\begin{equation*}
R^2 = r^2 + \sr^2 - 2r \sr \cos\omega
\end{equation*}

\end{document}


• Grazie. Appreciate the help. – grfrazee Feb 24 '17 at 9:39