# Horizontal spacing between lines in split environment

I have a math expression that looks like this

\documentclass[a4paper,12pt,amsmath,amssymb]{article}

\usepackage[utf8x]{inputenc}
\usepackage{ucs}
\usepackage[T1]{fontenc}
\usepackage{tgtermes}
\usepackage[croatian]{babel}
\usepackage{mathtools}

\begin{document}

\begin{equation*}
\begin{split}
&(m-n)[L_{m+n},L_p]+(n-p)[L_{n+p},L_m]+(p-m)[L_{p+m},L_n]=0\\
&(m-n)\left[(m+n-p)L_{m+n+p}+c(m+n)\delta_{m+n,-p}\right]+\\
&(n-p)\left[(n+p-m)L_{m+p+n}+c(n+p)\delta_{n+p,-m}\right]+\\
&(p-m)\left[(p+m-n)L_{p+m+n}+c(p+m)\delta_{p+m,-n}\right]=0\\
&(m-n)c(m+n)\delta_{m+n,-p}+(n-p)c(n+p)\delta_{n+p,-m}+\\
&+(p-m)c(p+m)\delta_{p+m,-n}=0\\
&(m-n)c(m+n)\delta_{m+n,-p}+(n+m+n)c(n-m-n)+\\
&+(-n-m-m)c(-n-m+m)=0\\
&(m-n)c(m+n)\delta_{m+n,-p}+(m+2n)c(-m)+(-n-2m)c(-n)=0\\
&\left[(m-n)c(m+n)-(n+2m)c(m)+(n+2m)c(n)\right]\delta_{n+p+m,0}=0
\end{split}
\end{equation*}

\end{document}


Now I tried by setting \hspace{5mm} between lines that have =0 in them (first line, fourth line, etc.), so that I have some kind of self contained portions in the expression, so that the reader could see that this is just a manipulation of the first expression. But \hspace did nothing. Is there a way to do this? I would like to separate certain parts, so that they stand out a bit, but not actually separating the whole expression (I hope I'm clear enough).

EDIT:

Here's a sketch what I want

I might mean vertical spacing, I always confuse those two xD

• Where should the extra space go, exactly? Did you mean vertical spacing? Could you post a sketch of the desired output? – jub0bs Nov 11 '13 at 20:38
• You want something like \\[2ex] at the places after which you want bigger vertical space. – egreg Nov 11 '13 at 20:50
• @Karlo You don't have to fix every single little typo you find on the site. It's good that you do "maintenance", but also consider that when you do a lot of edits at once you're flooding the front page, so new questions that need more attention disappear quickly. And I would say think twice if you're only fixing one or two typos. If more substantial edits are needed, including tags and formatting, that's another story. Main point: try to do such things in smaller batches. – Torbjørn T. Apr 29 '16 at 12:17
• @Karlo See also meta.tex.stackexchange.com/questions/340/… (And to make sure other commenters are notified of your comment, you need to use @username as I did here. Tab completion is usually available.) – Torbjørn T. Apr 29 '16 at 12:35
• @TorbjørnT. OK, didn't know that. – Karlo Apr 29 '16 at 12:41

You can use \\[<dimen>] at the end of a line in align, split and similar alignment environments. I guess that
<equation>\\[2ex]