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}

Denis · Accepted Answer

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}

egreg · Answer

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?

Alignment in cases environment with hphantom

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