Dear all,

I am a bit lost on how to split the bra ket operator `langle <?> mline <?> rangle`

. I am aware of the manual which says:

For scaled brackets use

noneas the bracket namea = left ( a over b right none newline left none phantom {a over b} + c right )

[…]

Be sure to put spaces (gaps) between elements when entering them directly in the Commands window. This ensures that the correct

structure is recognized.

therefore to represent this

I used the followings

```
iℏ d over {dt} none mline ψ(r ,t) rangle = H none mline ψ( r ,t) rangle
```

and

```
iℏ d over {dt} phantom mline ψ(r ,t) rangle = H phantom mline ψ( r ,t) rangle
```

but the results are both wrong because these are not brackets in the sense intended from the manual. How can I proceed?

Thank you for your time!