How can I use the physics package in mathjax for org-mode HTML export?

Question

I’m trying to use org-mode to export something as an HTML document, with MathJax equations. I know that MathJax supports the physics package, so it seems like it should be possible to tell emacs to tell MathJax to load physics. But how?

The code suggested in the link above is

window.MathJax = {
  loader: {load: ['[tex]/physics']},
  tex: {packages: {'[+]': ['physics']}}
};

so I tried putting variations of these lines in the document:

• #+HTML_MATHJAX: loader: {load: ['[tex]/physics']} tex: {packages: {'[+]': ['physics']}}
• #+HTML_MATHJAX: load: ['[tex]/physics'] packages: {'[+]': ['physics']}

But neither worked. What’s the right way to do this?

Example:

#+TITLE: Some physics
^^^ What can I put here to use the physics package?

$\ket{-}=\frac{\ket{0}-\ket{1}}{\sqrt{2}}$

Edit: I put one solution down below that uses pandoc.

Answer 1

I've probably looked through every single piece of documentation related to Org Mode's LaTeX to HTML export and MathJax, and this is what I've got:

Launch Emacs, then open up your MathJax configuration using M-x org-customize. Go to Org Export -> Org Export HTML -> Org HTML MathJax template. There, you will find a window where you can edit the MathJax config.

Change it up so it looks like this:

<script type="text/x-mathjax-config">
MathJax.Hub.Config({
    displayAlign: "%ALIGN",
    displayIndent: "%INDENT",

    extensions: ["[Contrib]/physics/physics.js"],

    "HTML-CSS": { scale: %SCALE,
                    linebreaks: { automatic: "%LINEBREAKS" },
                    webFont: "%FONT"
                   },
    SVG: {scale: %SCALE,
          linebreaks: { automatic: "%LINEBREAKS" },
          font: "%FONT"},
    NativeMML: {scale: %SCALE},
    TeX: { equationNumbers: {autoNumber: "%AUTONUMBER"},
           MultLineWidth: "%MULTLINEWIDTH",
           TagSide: "%TAGSIDE",
           TagIndent: "%TAGINDENT"}
         }
});
</script>
<script type="text/javascript"
        src="%PATH"></script> 

The important line to add is:

extensions: ["[Contrib]/physics/physics.js"],

When you're in this editing mode the <return> key might not add a whitespace character. Remember that you can always add one using the C-o shortcut. After you're done select [ Apply and save ]. Now the physics package should be working properly.

Answer 2

Okay, this works for my specific case (thanks to Ian’s comment):

1. Install the package ox-pandoc.
2. Customize the option org-pandoc-options-for-html5 to include mathjax set to t.
3. Run the command org-pandoc-export-to-html5.