# Braket size problem

I have a braket term in an equation. The bra size is bigger than the ket size due to a primed item in the bra part. I know that \big function can make ket size bigger and it can match the height but i want to make the bra size smaller:

\documentclass[phys]
\begin{document}
$$\bra{\vec{q'}}\ket{\vec{q}}$$
\end{document}


Do you have any suggestions ?

Thanks in advance

• Welcome to TEX.SE! A minimal working example would be helpful here. In particular: what exactly are you using to make bras and kets? The answer may depend on that. – campa Aug 17 '16 at 14:04
• there are many definitions for brakes notation that will ensure teh sizes match,. what definition are you using for bra and ket here? (please always make your example complete, so people can run it) – David Carlisle Aug 17 '16 at 14:05
• @user175924 What is \documentclass[phys] ? If possible, try to give an example with \documentclass{article}. phys is not known to me, where do you have it from? And the []-notation looks wrong. Should be {} – LaRiFaRi Aug 17 '16 at 14:20
• as rude solution: \ket{\vec{q\vphantom{'}}, maybe it can help in time of searching for better solution :-) – Zarko Aug 17 '16 at 14:54
• @Zarko -- but that would make the prime invisible. not what's wanted. \smash would be more appropriate. – barbara beeton Aug 17 '16 at 14:57

## 2 Answers

this is not an answer, but a demonstration of possibilities.

the code shown in the question doesn't exhibit the described result, namely that the left angle bracket is larger than the right one.

edit: since the request was for a smaller set of brakets, i've added examples showing that the shapes used around the q are the smallest default size. to get smaller ones, one has to go to ridiculous lengths, explicitly specifying a different (and inappropriate) size.

\documentclass[12pt]{article}
\usepackage{braket}
\usepackage{amsmath}
\begin{document}
\begin{equation*}
\bra{\vec{q'}}\ket{\vec{q}} \quad
\bra{\vec{a'}}\ket{\vec{a}} \quad
\bra{a'}\ket{a} \quad
{\scriptstyle \bra{{\textstyle{a'}}}\ket{\textstyle{a}}}
\end{equation*}

\begin{equation*}
\bra{\vec{q}\,\smash{'}}\ket{\vec{q}\,} \quad
\bra{\vec{a}\,\smash{'}}\ket{\vec{a}\,}
\end{equation*}

\begin{equation*}
\bra{\vphantom{a}\smash{\vec{q'}}}\ket{\vec{q}\,} \quad
\bra{\smash{\vec{a'}}}\ket{\vec{a}\,}
\end{equation*}
\end{document}


note that the coding here isn't good style -- never use multiple adjacent equation environments. and i've also taken liberties with spacing, since it's not really clear what is wanted.

edit:
it has come to my attention (by way of a comment on Increase in bracket sizes due to power symbol) that the physics package also supports the \bra \ket notation, and according to texdoc physics you can apply a * to suppress automatic sizing (see page 6).

• Thank you so much, but as I said, I want to make my bracket size smaller. at least now I know how to make the smaller ones bigger and how to arrange the vector sign :)) – user175924 Aug 19 '16 at 10:34
• Hello again ! I still have this issue, I was wondering if it is possible to produce the first example as one complete bracket instead of two separate items, such as \bra{\vec{q^{\prime}}}\hat{H}\ket{\vec{q}}) – user175924 Sep 21 '16 at 13:24
• @user175924 -- i'm afraid i don't understand your question. the code you show produces the bra-ket parts at the (same) expected size, with the embellished H between them. it's no different from your original question. – barbara beeton Sep 21 '16 at 14:12
• Unfortunately it does not produce the bracket at the same size in my tex. Because of the prime , bra size is bigger than ket size. – user175924 Sep 22 '16 at 14:34
• @user175924 -- you are using \documentclass{phys}. we don't know what that is, or where to get it. unless we have that information, we aren't able to help any more than we already have. – barbara beeton Sep 22 '16 at 14:44

Suggest to try a simple

\bigl<\ve{q}^{\,\prime}\bigl|\ve{q}\,\bigr>\bigr.


in article document class.

• The commands \bigl, \ve and \bigr are undefined in any standard document, please ensure answers give everything necessary for compilation, ideally providing complete and compilable code. – Dai Bowen Sep 23 '16 at 19:23
• @DaiBowen -- while \ve is certainly not defined everywhere, \bigl and \bigr are tex primitives, so if they're not recognized, the tex engine being used isn't conformant. – barbara beeton Sep 23 '16 at 20:11