[Tex/LaTex] Are \choose and \align incompatible

Question

I ran across a strange warning when trying to use the math command \choose inside the amsmath package's \align* environment:

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align*}
{n \choose k}
\end{align*}
\end{document}

Package amsmath Warning: Foreign command \atopwidthdelims; \frac or \genfrac should be used instead

The document still compiles and produces perfectly fine output. But what is causing this warning? And is there a way to get rid of it?

Answer 1

Do not use {n \choose k} in LaTeX (it is a plain TeX command). The recommended way in LaTeX is \usepackage{amsmath} in the preamble and then \binom{n}{k}. (You have then also \tbinom and \dbinom for text and display styles also.)