Alignment in cases environment with \hphantom

Question

I am using the \hphantom command to center the middle 0, but the middle 0 is still too far left.

Here is a picture of my problem:

Here is my MWE:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}


\begin{document}

\begin{align}
    \Delta G = 
    \begin{cases}
            < 0 & \quad A\\
            \hphantom{<}  0 &  \quad B\\
            > 0 & \quad C \\ 
    \end{cases}
\end{align}

\end{document}

Answer 1

You can do (quick and dirty)

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}


\begin{document}

\begin{align}
    \Delta G =
    \begin{cases}
            < 0 & \quad A\\
            \hphantom{< \mbox{}}  0 &  \quad B\\
            > 0 & \quad C \\
    \end{cases}
\end{align}

\end{document}

Answer 2

You need an empty relation symbol with the same width as > (or <):

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\begin{equation}
\Delta G =
  \begin{cases}
  < 0 & A\\
  \mathrel{\phantom{<}} 0 & B\\
  > 0 & C
  \end{cases}
\end{equation}

\end{document}

I wouldn't add \quad. Avoid the trailing \\; while it has no effect in this particular case, it would have in align or similar constructions, producing an empty line. Also avoid align for a single equation.

But why not using =0?