I get an error message on 64-bit MikTex for the following minimal example:
\documentclass{article}
\usepackage{physics}
\begin{document}
Hello world
\end{document}
What can be possibly going wrong? I tried everything I know.
[Tex/LaTex] Unable to include the physics package
physics
Related Solutions
\dot is a command requiring a parameter, to set a dot above some character, to indicate the time derivative. The multiplication dot can be obtained using \cdot!
Another error were the missing \ (but without complaining) just before abs.
Please don't use the outdated $$....$$ syntax -- use \[....\] instead.
\documentclass{book}
\usepackage{physics}
\begin{document}
\LARGE
\[ \va{A} \cdot \va{B} = \abs{A}\cdot \abs{B}\cdot \cos{\theta}\]
\end{document}
A solution using mathtools:
\documentclass{revtex4-1}
\usepackage{mathtools}
\DeclarePairedDelimiter\abs{\lvert}{\rvert}
\DeclarePairedDelimiterX\phys[3]{\langle}{\rangle}{#1 \delimsize\vert\mathopen{} #2 \delimsize\vert\mathopen{} #3}
\newcommand*\Vector[1]{\boldsymbol{#1}}
\begin{document}
\begin{equation}
\abs*{\prescript{}{u}{\phys*{\nu,\Vector{0}}{\Vector{k} \cdot \Vector{p}}{\nu',\Vector{0}}}_{u}}^{2}
\end{equation}
\end{document}
For your particular problem, the \prescript macro is the key.
Best Answer
Your
.logfile seems to show that bothxparse.styandexpl3.styare located in the same folder as your.texfile, while they should have been inc:/texlive/2017/..., as is the case withl3names.sty. The first place LaTeX looks for files is, I think, the current folder. So presumably, if you delete those local copies ofxparseandexpl3(or even have the.texfile in a different folder), it would work.