\documentclass{article}
\pagestyle{empty}
\usepackage{graphicx}
\makeatletter
\newcommand\widegrave[1]{%
\mathpalette\@wideaccent{{#1}{\mathchar"7012}}%
}
\newcommand\wideacute[1]{%
\mathpalette\@wideaccent{{#1}{\mathchar"7013}}%
}
\newcommand*\@wideaccent[2]{%
\@@wideaccent{#1}#2%
}
\newcommand\@@wideaccent[3]{%
\setbox\@tempboxa\hbox{$\m@th#1#2$}%
\@tempdima=\ht\@tempboxa
\@tempdimb=\wd\@tempboxa
\ooalign{%
\box\@tempboxa\cr
\hidewidth\raise\dimexpr\@tempdima-1ex\relax\hbox{\resizebox{\@tempdimb}{\height}{$\m@th#1#3$}}\hidewidth
}%
}
\makeatother
\begin{document}\noindent
Gut: \(\grave{a}\) \ldots\ \(\grave{z}\) \(\grave{A}\) \ldots\ \(\grave{Z}\) \(\grave{\alpha}\) \ldots\ \(\grave{\omega}\) \(\grave{\Gamma}\) \ldots\ \(\grave{\Omega}\) \(\grave{\aleph}\) \(\varphi^{\grave{a}}\) \ldots\ \(\varphi^{\grave{z}}\) \(\varphi^{\grave{A}}\) \ldots\ \(\varphi^{\grave{Z}}\) \(\varphi^{\grave{\alpha}}\) \ldots\ \(\varphi^{\grave{\omega}}\) \(\varphi^{\grave{\Gamma}}\) \ldots\ \(\varphi^{\grave{\Omega}}\) \(\varphi^{\grave{\aleph}}\)\\
Relativ gut: \(\widegrave{lang}\) \(\varphi^{\widegrave{lang}}\) \(\varphi_{\widegrave{lang}}\)\\
Schlecht: \(\grave{lang}\) \(\varphi^{\grave{lang}}\) \(\varphi^{\widegrave{v_1}}\) \(\varphi_{\grave{lang}}\) \(\varphi_{\widegrave{v_1}}\)
\end{document}