${\displaystyle {\ce {H-C\equiv C-{\overset {\displaystyle H \atop |}{\underset {| \atop \displaystyle H}{C}}}-{\overset {\displaystyle H \atop |}{\underset {| \atop \displaystyle H}{C}}}-H}}}$

In your article, replace the image with:

<chem>H-C \equiv C-
\overset{\displaystyle H \atop | }{\underset{ | \atop \displaystyle H}{C} }-
\overset{\displaystyle H \atop | }{\underset{ | \atop \displaystyle H}{C} }-
H</chem>