I want to change the bibliography title 'Literatur' in 'Literaturverzeichnis', but it doesn't work with \addto\captionsngerman{\renewcommand{\refname}{Literaturverzeichnis}}.
\documentclass[12pt,twoside,parskip=half-,numbers=noenddot,BCOR=8mm,headheight=29pt]{scrartcl}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@article{greenwade93,
author = "George D. Greenwade",
title = "The {C}omprehensive {T}ex {A}rchive {N}etwork",
year = "1993",
journal = "TUGBoat",
volume = "14",
number = "3",
pages = "342--351"
}
\end{filecontents}
\usepackage[backend=biber,style=alphabetic,maxnames=10]{biblatex}
\addbibresource{\jobname.bib}
\begin{document}
\cite{greenwade93}
\printbibliography[heading=bibintoc]
\end{document}

\DefineBibliographyStrings{german}{references = {Literaturverzeichnis},}or switch toabbreviate=false(works for (n)German because "Literatur" is the short form and "Literaturverzeichnis" the long). Of course the latter will change other things as well. – moewe Sep 28 '16 at 14:54