\documentclass{standalone}
\usepackage{tikz}
\usepackage{graphene}
\begin{document}
\begin{tikzpicture}

% draw grids
\graphene{(0,0)}{}
\graphene{(-1,0)}{dashed}

\sitelattice{at}{(-1,0)}{}
\sitelattice{bt}{(-1,0)}{}
\sitelattice{a}{(0,0)}{}
\sitelattice{b}{(0,0)}{}

\end{tikzpicture}
\end{document}