
\documentclass[border=5pt,multi=true]{standalone}
\usepackage{standalone}
\usepackage{ifthen}
\usepackage{threeparttable}
\usepackage{microtype}
\usepackage{lineno}
\usepackage{xspace}
\usepackage{caption}
\usepackage{graphicx}
\usepackage{color}
\usepackage{colortbl}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{upgreek}
\usepackage{hyperxmp}
\usepackage{hyperref}
\usepackage{hypcap}
\usepackage{xspace}
\usepackage{upgreek}
\usepackage{cite}
\usepackage{mciteplus}
\usepackage{longtable}

\begin{document}
\small


  \begin{tabular}{ l |llll}
\hline
                  &  $ x_-$ \xspace &  $ y_-$ \xspace &  $ x_+$ \xspace &  $ y_+$ \xspace\\
\hline
 $ x_-$ \xspace             &  $\phantom{-}1$ &  $-0.247$ &  $\phantom{-}0.038$ &  $-0.003$  \\
 $ y_-$ \xspace             &  $-0.247$ &  $\phantom{-}1$ &  $-0.011$ &  $\phantom{-}0.012$  \\
 $ x_+$ \xspace             &  $\phantom{-}0.038$ &  $-0.011$ &  $\phantom{-}1$ &  $\phantom{-}0.002$  \\
 $ y_+$ \xspace             &  $-0.003$ &  $\phantom{-}0.012$ &  $\phantom{-}0.002$ &  $\phantom{-}1$  \\
\hline
\end{tabular}
\end{document}
