# Tikz-Feynman manual placement vertex style

I'm drawing a Feynman diagram using Tikz-Feynman's manual placement:

\begin{tikzpicture}
\begin{feynman}
\vertex [label=left:$$x_1$$] (a) at (0,0);
\vertex (b) at (1,-1);
\vertex (c) at (2,-2);
\vertex (d) at (3,-3);
\vertex [label=right:$$x_2$$] (e) at (6,0);
\vertex [label=right:$$x_4$$] (g) at (6,-6);
\vertex [label=left:$$x_3$$] (f) at (0,-6);

\diagram*{
(a)  -- (b) -- [half left] (c) -- [half left] (b),
(c) -- (d) -- (e),
(f) -- (d) -- (g)
};
\end{feynman}
\end{tikzpicture}


The result of which is:

I would like each endpoint vertex (at the x's) to be a small black dot, but I can't figure out how to do so. I have seen this question, but simply adding 'dot' to the square brackets doesn't seem to do anything. Adding (a) [dot] within the \diagram environment also doesn't have any effect. Any ideas?

• Please extend your code fragment to an MWE which we can test as it is! Mar 15, 2020 at 13:13

I found a solution. Apparently there is a bug which causes this. The issue is solved by using \node instead of \vertex. My code now looks like this:

\begin{tikzpicture}
\begin{feynman}
\node [dot,label=left:$$x_1$$] (a) at (0,0);
\vertex (b) at (1,-1);
\vertex (c) at (2,-2);
\vertex (d) at (3,-3);
\node [dot,label=right:$$x_2$$] (e) at (6,0);
\node [dot,label=right:$$x_4$$] (g) at (6,-6);
\node [dot,label=left:$$x_3$$] (f) at (0,-6);

\diagram*{
(a)  -- (b) -- [half left] (c) -- [half left] (b),
(c) -- (d) -- (e),
(f) -- (d) -- (g)
};
\end{feynman}
\end{tikzpicture}


Which looks like this:

the syntax at page 19 of the manual uses this syntax for dashed line

• I think you misunderstood the question. I want each vertex to be a small black dot, not the edges to be dotted lines. I will edit the question to be clearer on this Mar 15, 2020 at 11:49