Krdytkyu

I am in the situation of using intertext/shortintertext with the Revtex document class, but it seems there are some spacing issues.

Consider:

documentclass[aps,prl,reprint]{revtex4-1}

% documentclass{article}

usepackage{mathtools}

usepackage{bm}

usepackage{newtxtext,newtxmath}

usepackage{lipsum}



begin{document}

lipsum*[1]

begin{subequations}

    begin{align}

    varepsilon_0(bm{q}) &= varepsilon_1(bm{q}) = 0 \

    varepsilon_2(bm{q}) &=beta bigl[ 4(1 - J') + 4J' Q - 2(1+2J')sqrt{1+Q} , bigr]\

    varepsilon_3(bm{q}) &= beta bigl[4(1 - J') + 4J' Q + 2(1+2J')sqrt{1+Q} , bigr] ,, \

    shortintertext{and}

    Q &= a + b + c + d + e + f - 3

    end{align}

end{subequations}

lipsum*[1-3]

end{document}

and there is large spacing before and after the and text.
This is not present if I switch out the document class to article, so how to fix this?

ps. Strangely, using shortintertext gives rise to a larger spacing than intertext.. why is this so?

You can modify the vertical space before and after both intertext and shortintertext: here's a possibility, adjust to suit your needs.

documentclass[aps,prl,reprint]{revtex4-1}

usepackage{mathtools}

usepackage{newtxtext,newtxmath}

usepackage{bm}

usepackage{lipsum}



mathtoolsset{

  above-shortintertext-sep=-belowdisplayshortskip,

  below-shortintertext-sep=-abovedisplayskip,

  above-intertext-sep=0pt, % default

  below-intertext-sep=-.5abovedisplayskip,

}



begin{document}

lipsum*[1]

begin{subequations}

begin{align}

varepsilon_0(bm{q}) &= varepsilon_1(bm{q}) = 0 \

varepsilon_2(bm{q}) &=beta bigl[ 4(1 - J') + 4J' Q - 2(1+2J')sqrt{1+Q} , bigr]\

varepsilon_3(bm{q}) &= beta bigl[4(1 - J') + 4J' Q + 2(1+2J')sqrt{1+Q} , bigr] ,, \

shortintertext{and}

Q &= a + b + c + d + e + f - 3

end{align}

end{subequations}

lipsum*[4]

begin{subequations}

begin{align}

varepsilon_0(bm{q}) &= varepsilon_1(bm{q}) = 0 \

varepsilon_2(bm{q}) &=beta bigl[ 4(1 - J') + 4J' Q - 2(1+2J')sqrt{1+Q} , bigr]\

varepsilon_3(bm{q}) &= beta bigl[4(1 - J') + 4J' Q + 2(1+2J')sqrt{1+Q} , bigr] ,, \

intertext{and}

Q &= a + b + c + d + e + f - 3

end{align}

end{subequations}

lipsum

end{document}

I propose this work-around: use the optional argument for intertext, introduced by package nccmath:

documentclass[aps,prl,reprint]{revtex4-1}

% documentclass{article}

usepackage{newtxtext,newtxmath}

usepackage{mathtools, bm, nccmath}

usepackage{lipsum}



begin{document}



lipsum*[1]

begin{subequations}

    begin{align}

    varepsilon_0(bm{q}) &= varepsilon_1(bm{q}) = 0 \

    varepsilon_2(bm{q}) &=beta bigl[ 4(1 - J') + 4J' Q - 2(1+2J')sqrt{1+Q} , bigr]\

    varepsilon_3(bm{q}) &= beta bigl[4(1 - J') + 4J' Q + 2(1+2J')sqrt{1+Q} , bigr] ,, \

    intertext[0 ex]{and}

    Q &= a + b + c + d + e + f - 3

    end{align}

end{subequations}

lipsum*[1-3]



end{document}