# Tuning alignment when using simplewick for subscripts

I'm trying to reproduce this equation, which uses simplewick to connect tensor indices. If it matters, it is not a Wick contraction.

Here is an MWE that I compile with latexmk -pdf example.tex:

\documentclass{article}

\usepackage{simplewick}

\begin{document}

$$\bcontraction[4pt]{K4 = v}{{}_i}{_{jP}v^{PQ}v_{klQ}\sigma}{{}_a} \bcontraction[6pt]{K4 = v_{i}}{{}_j}{_{j}v^{PQ}v_{klQ}\sigma_{a}^{k}\sigma}{{}_b} K4 = v_{ijP}v^{PQ}v_{klQ}\sigma_{a}^{k}\sigma_{b}^{l}$$

\end{document}


Now, I think this reproduces it exactly, and in fact it has better alignment under b than the example. So, I think it's close enough to have the intent of the contractions understood. But, it's still not perfect, because the line is too far right of the a and the j.

• Is there any way to fine-tune the alignment of the contractions? In particular, I'm not sure if the two contractions are optimally specified.

I think I'd be allowed to package a modified style file with my source. Note that I cannot switch to simpler-wick, since I don't think the journal I'm submitting to allows xelatex and TikZ, which simpler-wick requires.

• Welcome to TeX.SX! You could ask the journal to use xelatex or TikZ. I can compile with pdflatex, but not with latexmk. – Bobyandbob Oct 18 '17 at 16:03
• @Bobyandbob I could, but they offer almost no details on their compilation and state "Use additional packages only when they are required to support your content", so I think I'd rather deal with my solution than force a switch unless I want to do something that just looks horrific without simpler-wick. I also forgot to mention I can't get underbars to work with simpler-wick, which I need. I was also under the impression that latexmk called pdflatex by default...it shouldn't make a difference for my MWE. – pentavalentcarbon Oct 18 '17 at 16:10

\documentclass{article}
$$\bcontraction[4pt]{K4 = v}{{}_i}{_{jP}v^{PQ}v_{klQ}\sigma}{{}_a\!}\, \bcontraction[6pt]{K4 = v_{i}}{{}_j\!}{\,_{j}v^{PQ}v_{klQ}\sigma_{a}^{k}\sigma}{{}_b} K4 = v_{ijP}v^{PQ}v_{klQ}\sigma_{a}^{k}\sigma_{b}^{l}$$