I am using `\langle`

and `\rangle`

to type Dirac brakets. But the symbols can not resize automatically to fit the symbols inside, as this:

But document here shows a right example without explaining how to put it:

So how to accomplish this?

# How to type Dirac Braket properly

The brackets you can enter by typing `<`

, followed by the Tab key six times.

You can get the right size separating symbol `|`

by typing `|`

and Tab twice.

I have tried type `<`

and `tab`

but give up mid way… And I just found one can put `<`

and `shift+tab`

to save more time. Or maybe users can change the cyclic order of `<`

by themselves?

I found it is easy to type Bra, just type `|`

after I have typed `<`

and `shift+tab`

. But how to type Ket more conveniently?

You can do `<`

and `Shift-Tab`

, then put the cursor in front of `<>`

and press Delete, then `|`

.

You can use `ALT+L`

followed with `<`

to type langle, and `ALT+R`

followed with `>`

to type rangle. Besides, to type `|`

inside the Dirac Braket, just use `ALT+M`

followed with `|`

. These three `ALT+L/M/R`

prefix keys can actually be used with all types of brackets. Note that all `ALT+R`

keys must be preceded with `ALT+L`

keys. Sometimes, these prefix keys can be omitted. For example, to type Ket, you can just type `|`

and `ALT+R`

with `>`

; and to type Bra, just use `ALT+L`

with `<`

and `|`

.

Maybe you can try to create commands to simplify every input operation of Dirac notation. Here is my programme

It is easy to input most of them without macros.

For bra’s: first input `{`

, then press Tab to get `⟨⟩`

, and input, say, `a`

, and then `|`

, you will get `⟨a|`

.

For pro’s and mel’s, the same steps as above, and after inputting `|`

, you press Tab, getting `⟨a|⟩`

.

To get ave’s, you just do the first two steps for bra’s.

It is slightly more difficult to input kets. You first input things like `⟨a⟩`

, then remove `⟨`

and replace it by `|`

.

For kets in the math mode, there are no difficulties either since they follow the same pattern. First, input `|`

to get `||`

, then input, for example, `a`

, and finally `}`

, you will get `|a}`

, and pressing `Tab`

will yield `|a⟩`

.

For more details on asymmetric brackets, please refer to *The Jolly Writer* Chapter 4.5.

I started a physics style package plugin:

We can work together to improve it. I just added `ket`

, `ket*`

, `bra`

, `bra*`

.

You can follow the pattern add more macros as an equiv of the LaTeX physics package.