I want to put bar over a alphabet, but outside in math mode. how do I do it?

Question

I am trying to write bar symbol with some alphabets inside \begin{equation} \end{equation} like this,

\begin{equation}

H \bar{k} 

\end{equation}

I have more than one alphabet to give bar. I've showed only one though.

It shows a lot of error as it is in out of math mode. How do I give bar in this equation mode?

Answer 1

The command \= is the text mode equivalent of \bar.