# Adjust space between base and superscript

I noticed that, in math mode, the top right corner of some letters, such as N or K, seems to clip into the superscript that follows the letter. I'm attaching an example:

I guess a local solution could be to write $N^{\ 2}$ instead, but I was wondering if there exists a global solution, so that I do not have to manually insert the spacing every time.

I am aware of solutions such as this one or this one, however I believe the answer to the first one refers specifically to mathcal, while the second one concerns superscripts preceding the letter.

In case it could be helpful, here's the preamble to my document. I am using XeLaTeX to compile.

\documentclass[10pt,a4paper]{book}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{mathspec}
\defaultfontfeatures{Mapping=tex-text}
\setallmainfonts{Old Standard}


Thanks.

• The local solution is a little toomuch. Maybe try N^{\mkern 1.5mu 2} (half a thin insecable space). Perhaps it is mathspec flaw? – Bernard Jul 16 '19 at 13:49
• @Bernard that does indeed look better. If anyone knows of a global solution, of course, that would be even better. – user192881 Jul 16 '19 at 15:05

A possible solution (is not the best):

\documentclass[10pt,a4paper]{book}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{mathspec}
\defaultfontfeatures{Mapping=tex-text}
\setallmainfonts{Old Standard}
\begin{document}
$N{\,}^2$
\end{document}