A version 4.0 of my package bundle chemmacros is coming nearer. The most notable difference will be that the chemformula package will be usable as a standalone package. This is not what I am going to ask you about. You may know that chemmacros provides some orbital pictures:

\orbital{s} \orbital{p} \orbital{sp3}

Now, I want to add picture for d-Orbitals. This is what I have for the :

I’m not really sure which one I like better. I don’t like both of them very much. Maybe you have ideas for improvements?

\begin{tikzpicture}[
inner sep=0 , outer sep=0 , line width=.2pt ,
rotate = { 90 - 90 } ,
baseline ,
minimum size = 0

]
draw = black ,
ball color = black!90

]
(0,0) .. controls ++ ( - 1 * 2em , - 1 * 2em )
and ++ ( 1 * 2em , - 1 * 2em )
.. (0,0);
draw = black ,
ball color = black!90

]
(0,0) .. controls ++ (- 1 * 2em , 1 * 2em )
and ++ ( 1 * 2em , 1 * 2em )
.. (0,0);
\end{tikzpicture}
\begin{tikzpicture}[
inner sep=0 , outer sep=0 , line width=.2pt ,
rotate = { 90 - 90 } ,
baseline ,
minimum size = 0

]
draw = black ,
ball color = black!90

]
(0,0) .. controls ++ ( - 1 * 2em , - 1 * 2em )
and ++ ( 1 * 2em , - 1 * 2em )
.. (0,0);
draw = black ,
ball color = black!90

]
(0,0) .. controls ++ (- 1 * 2em , 1 * 2em )
and ++ ( 1 * 2em , 1 * 2em )
.. (0,0);
\end{tikzpicture
}

The and friends are a bit better — they’re simply combinations of the existing p-orbitals — but not perfect either. I’m open to suggestions, improvements, comments, …

\begin{tikzpicture}[
inner sep=0 , outer sep=0 , line width=.2pt ,
rotate = { 0 - 45 } ,
baseline ,
minimum size = 0

]
draw = black ,
ball color = black!90

]
(0,0) .. controls ++ (- 1 * 2em , 1 * 2em )
and ++ ( 1 * 2em , 1 * 2em )
.. (0,0);
draw = black!5 ,
ball color = black!5 ,
rotate = 135 ,

]
(0,0) .. controls ++ ( - 1 * 2em , - 1 * 2em )
and ++ ( 1 * 2em , - 1 * 2em )
.. (0,0);
draw = black!5 ,
ball color = black!5 ,
rotate = 135 ,

]
(0,0) .. controls ++ (- 1 * 2em , 1 * 2em )
and ++ ( 1 * 2em , 1 * 2em )
.. (0,0);
draw = black ,
ball color = black!90

]
(0,0) .. controls ++ ( - 1 * 2em , - 1 * 2em )
and ++ ( 1 * 2em , - 1 * 2em )
.. (0,0);
\end{tikzpicture}
\begin{tikzpicture}[
inner sep=0 , outer sep=0 , line width=.2pt ,
rotate = { 0  } ,
baseline ,
minimum size = 0

]
draw = black ,
ball color = black!90 ,
rotate = 0

]
(0,0) .. controls ++ (- 1 * 2em , 1 * 2em )
and ++ ( 1 * 2em , 1 * 2em )
.. (0,0);
draw = black!5 ,
ball color = black!5 ,
rotate = -90 ,

]
(0,0) .. controls ++ ( - 1 * 2em , - 1 * 2em )
and ++ ( 1 * 2em , - 1 * 2em )
.. (0,0);
draw = black!5 ,
ball color = black!5 ,
rotate = -90 ,

]
(0,0) .. controls ++ (- 1 * 2em , 1 * 2em )
and ++ ( 1 * 2em , 1 * 2em )
.. (0,0);
draw = black ,
ball color = black!90 ,
rotate = 0

]
(0,0) .. controls ++ ( - 1 * 2em , - 1 * 2em )
and ++ ( 1 * 2em , - 1 * 2em )
.. (0,0);
\end{tikzpicture
}

1. Guntram

Hi!

The white part doesn’t seem to be easily visible…maybe more of a gray type?
Will coloring (blue/red, e.g.) be available?

For the “ring” of the z²: It should be more round/donut-like. Not so flat, as it has been drawn.

The first of the dx²-dy²: it should be more tilted! Meaning the black part more horizontal and more “compressed” (depth)!

Just my 50cents ;-)

• Hi Guntram, thanks for your input!

It will be possible to choose custom colors so I hope colors are not the problem. :)

The problem with all of the orbital pictures is that they’re not really orbitals meaning they’re not the actual plots for the 99% probability of finding an electron. They’re just pictures made with TikZ resembling the actual plots. This means that by design they’re not going to look correct.

The ring is not drawn as a ring in the above pictures but as ellipses. For the first it is a filled ellipse and a smaller white one drawn above. The second one is a single ellipse with a thicker line width. If you (or anyone else) has a better or at least another idea I would love to hear it!

You’re right of course regarding the orbital. It looks awful. My TikZ-foo, unfortunately, is not that good. I’m open for ideas how to code a better one!

2. firsthuman

I am wondering if there is an option in chemmacros to write orbital names in a proper way or even electronic transitions like

\pi_v^* \rightarrow d_{x^2-y^2}

. In the package manual I was only able to find the possibility to draw orbitals; maybe this is planned in future versions?

• There is no such option in chemmacros, yet. I’ve been asked this before but I’m hesitating to add something. writing $d_{x^2-y^2}$ is not that complicated and I think there is nothing gained by a macro that hides it…

3. cornelussen

Hi,

There is a package called tikzorbitals, that also draws s, p and d orbitals and uses the command \orbital to do so. It is available on CTAN and is maintained by Germain Salvato-Vallverdu. I don’t know if you are familiar with this package.

Regards,
Thijs Cornelussen

• Hi.

Yes, I know of that package (it’s in my list of packages). I must admit though that I had forgotten about it.

Regards