Cfrgtkky

I'm pretty new to LaTeX, so sorry for the beginner question. I'm trying to align on equals signs within tabular, however a few rows are blank and don't have equals signs. How can I do this? Thanks!

documentclass{article}

usepackage[utf8]{inputenc}

usepackage{multirow, adjustbox, mathtools}

begin{document}



begin{table}[htbp]

begin{adjustbox}{width=columnwidth,center}

  begin{tabular}{|c|c|c|c|c|}

    hline

    Force Field & Calculated Energy & Calculated Difference & Experimental Difference & Error \

    hline



    multirow{4}{*}{OPLS-AA}

        & tt = 2.55447 & && \ cline{2-5}

        & $text{g}^+text{g}^+$ = 4.19785 & $text{g}^+text{g}^+$-tt = 1.64338 & $text{g}^+text{g}^+$-tt = 1.62 & 0.02338 \ cline{2-5}

        & $text{g}^+text{g}^-$ = 5.56306 & $text{g}^+text{g}^-$-tt = 3.00859 & $text{g}^+text{g}^-$-tt = 3.51 & -0.50141 \ cline{2-5}

        & tg = 3.36156 & tg-tt = 0.80709 & tg-tt = 0.86 & -0.05291 \ cline{2-5}

    hline



    multirow{4}{*}{AM1}

        & tt = -37.97281 & && \ cline{2-5}

        & $text{g}^+text{g}^+$ = -36.52659 & $text{g}^+text{g}^+$-tt = 1.44622 & $text{g}^+text{g}^+$-tt = 1.62 & -0.17378 \ cline{2-5}

        & $text{g}^+text{g}^-$ = -35.85939 & $text{g}^+text{g}^-$-tt = 2.11342 & $text{g}^+text{g}^-$-tt = 3.51 & -1.39658 \ cline{2-5}

        & tg = -37.25846 & tg-tt = 0.71435 & tg-tt = 0.86 & -0.14565 \ cline{2-5}

    hline



    multirow{4}{*}{PDDG/PM3}

        & tt = -34.61227 & && \ cline{2-5}

        & $text{g}^+text{g}^+$ = -33.94462 & $text{g}^+text{g}^+$-tt = 0.66765 & $text{g}^+text{g}^+$-tt = 1.62 & -0.95235 \ cline{2-5}

        & $text{g}^+text{g}^-$ = -33.29225 & $text{g}^+text{g}^-$-tt = 1.32002 & $text{g}^+text{g}^-$-tt = 3.51 & -2.18998 \ cline{2-5}

        & tg = -34.38819 & tg-tt = 0.22408 & tg-tt = 0.86 & -0.63592 \ cline{2-5}

    hline

  end{tabular}

end{adjustbox}

end{table}



end{document}

Here is one approach. I split the columns using = into two columns. To get the spacing right (and save typing) I used @{$null=null$} between the columns. Unfortunately, this meant having to use multicolumn every time I didn't want a = to appear.

The only remaining problem was that when the label is too large, the extra space is added to the right half. To fix that, I calculated the difference and added extra space to the left half using makebox. Now the equal signs are centered.

documentclass{article}

usepackage[utf8]{inputenc}

usepackage{multirow, adjustbox, mathtools}

begin{document}



begin{table}[htbp]

begin{adjustbox}{width=columnwidth,center}

  sbox0{Calculated Difference}%

  sbox1{Experimental Difference}%

  sbox2{$null=null$}%

  dimen0=dimexpr wd0 - wd2relax

  dimen1=dimexpr wd1 - wd2relax

  begin{tabular}{|c|r@{$null=null$}l|r@{$null=null$}l|r@{$null=null$}l|c|}

    hline

    Force Field & multicolumn{2}{c|}{Calculated Energy} & multicolumn{2}{c|}{Calculated Difference} & multicolumn{2}{c|}{Experimental Difference} & Error \

    hline

    multirow{4}{*}{OPLS-AA}

        & tt & 2.55447 & multicolumn{2}{c|}{} & multicolumn{2}{c|}{} & \ cline{2-8}

        & $text{g}^+text{g}^+$ & 4.19785 & makebox[0.5dimen0][r]{$text{g}^+text{g}^+$-tt} & 1.64338

          & makebox[0.5dimen1][r]{$text{g}^+text{g}^+$-tt} & 1.62 & 0.02338 \ cline{2-8}% note makebox

        & $text{g}^+text{g}^-$ & 5.56306 & $text{g}^+text{g}^-$-tt & 3.00859 & $text{g}^+text{g}^-$-tt & 3.51 & -0.50141 \ cline{2-8}

        & tg & 3.36156 & tg-tt & 0.80709 & tg-tt & 0.86 & -0.05291 \ cline{2-8}

    hline



    multirow{4}{*}{AM1}

        & tt & -37.97281 & multicolumn{2}{c|}{} & multicolumn{2}{c|}{} & \ cline{2-8}

        & $text{g}^+text{g}^+$ & -36.52659 & $text{g}^+text{g}^+$-tt & 1.44622 & $text{g}^+text{g}^+$-tt & 1.62 & -0.17378 \ cline{2-8}

        & $text{g}^+text{g}^-$ & -35.85939 & $text{g}^+text{g}^-$-tt & 2.11342 & $text{g}^+text{g}^-$-tt & 3.51 & -1.39658 \ cline{2-8}

        & tg & -37.25846 & tg-tt & 0.71435 & tg-tt & 0.86 & -0.14565 \ cline{2-8}

    hline

    multirow{4}{*}{PDDG/PM3}

        & tt & -34.61227 & multicolumn{2}{c|}{} & multicolumn{2}{c|}{} & \ cline{2-8}

        & $text{g}^+text{g}^+$ & -33.94462 & $text{g}^+text{g}^+$-tt & 0.66765 & $text{g}^+text{g}^+$-tt & 1.62 & -0.95235 \ cline{2-8}

        & $text{g}^+text{g}^-$ & -33.29225 & $text{g}^+text{g}^-$-tt & 1.32002 & $text{g}^+text{g}^-$-tt & 3.51 & -2.18998 \ cline{2-8}

        & tg & -34.38819 & tg-tt & 0.22408 & tg-tt & 0.86 & -0.63592 \ cline{2-8}

    hline

  end{tabular}

end{adjustbox}

end{table}



end{document}

If you really want to center the fields...

Note: I used a tabular in sbox3 mostly to show what you have to do it you are not sure which entry is the largest. Actually, 2.22222 and 2.22 would be close enough (2 is usually the widest digit).

documentclass{article}

usepackage[utf8]{inputenc}

usepackage{multirow, adjustbox, mathtools}

begin{document}



begin{table}[htbp]

begin{adjustbox}{width=columnwidth,center}

  sbox0{Calculated Difference}%

  sbox1{$null=null$}%

  sbox2{$text{g}^+text{g}^-$-tt}% left

  sbox3{begin{tabular}{@{}l@{}}

    1.64338\

    3.00859\

    0.80709\

    1.44622\

    2.11342\

    0.71435\

    0.66765\

    1.32002\

    0.22408

  end{tabular}}% right

  dimen0=dimexpr wd2 + wd0 - wd1 - wd3relax

  sbox0{Experimental Difference}%

  sbox3{begin{tabular}{@{}l@{}}

    1.62\

    3.51\

    0.86

  end{tabular}}% right

  dimen1=dimexpr wd2 + wd0 - wd1 - wd3relax

  begin{tabular}{|c|r@{$null=null$}l|r@{$null=null$}l|r@{$null=null$}l|c|}

    hline

    Force Field & multicolumn{2}{c|}{Calculated Energy} & multicolumn{2}{c|}{Calculated Difference} & multicolumn{2}{c|}{Experimental Difference} & Error \

    hline

    multirow{4}{*}{OPLS-AA}

        & tt & 2.55447 & multicolumn{2}{c|}{} & multicolumn{2}{c|}{} & \ cline{2-8}

        & $text{g}^+text{g}^+$ & 4.19785 & makebox[0.5dimen0][r]{$text{g}^+text{g}^+$-tt} & 1.64338

          & makebox[0.5dimen1][r]{$text{g}^+text{g}^+$-tt} & 1.62 & 0.02338 \ cline{2-8}% note makebox

        & $text{g}^+text{g}^-$ & 5.56306 & $text{g}^+text{g}^-$-tt & 3.00859 & $text{g}^+text{g}^-$-tt & 3.51 & -0.50141 \ cline{2-8}

        & tg & 3.36156 & tg-tt & 0.80709 & tg-tt & 0.86 & -0.05291 \ cline{2-8}

    hline



    multirow{4}{*}{AM1}

        & tt & -37.97281 & multicolumn{2}{c|}{} & multicolumn{2}{c|}{} & \ cline{2-8}

        & $text{g}^+text{g}^+$ & -36.52659 & $text{g}^+text{g}^+$-tt & 1.44622 & $text{g}^+text{g}^+$-tt & 1.62 & -0.17378 \ cline{2-8}

        & $text{g}^+text{g}^-$ & -35.85939 & $text{g}^+text{g}^-$-tt & 2.11342 & $text{g}^+text{g}^-$-tt & 3.51 & -1.39658 \ cline{2-8}

        & tg & -37.25846 & tg-tt & 0.71435 & tg-tt & 0.86 & -0.14565 \ cline{2-8}

    hline

    multirow{4}{*}{PDDG/PM3}

        & tt & -34.61227 & multicolumn{2}{c|}{} & multicolumn{2}{c|}{} & \ cline{2-8}

        & $text{g}^+text{g}^+$ & -33.94462 & $text{g}^+text{g}^+$-tt & 0.66765 & $text{g}^+text{g}^+$-tt & 1.62 & -0.95235 \ cline{2-8}

        & $text{g}^+text{g}^-$ & -33.29225 & $text{g}^+text{g}^-$-tt & 1.32002 & $text{g}^+text{g}^-$-tt & 3.51 & -2.18998 \ cline{2-8}

        & tg & -34.38819 & tg-tt & 0.22408 & tg-tt & 0.86 & -0.63592 \ cline{2-8}

    hline

  end{tabular}

end{adjustbox}

end{table}



end{document}