chemfig: enhancing code

I am reproducing the structure of the glass silicate lattice, where an oxygen atom bridges two silicon atoms

documentclass[12pt]{article}
usepackage[T1]{fontenc}
usepackage{lmodern}
usepackage{chemfig}



begin{document}

    schemestart
    chemfig{(Si(-[1]@{O1}O-[7]Si<:[5]O) (-[3]O)(<[5]O)(<:[7]O))}
    schemestop

end{document}

In particular, I had to write the oxygen atom twice with the dotted bonds. Is there a more elegant way of writing the same thing?

EDIT: Just the comment of the user, he asks this image taken from
https://favpng.com/png_view/sodium-silicate-silicon-oxygen-tetrahedron-chemistry-lewis-structure-quartz-png/JGt4RSXb

documentclass[12pt]{article}
usepackage[T1]{fontenc}
usepackage{lmodern}
usepackage{chemfig}

begin{document}
chemfig{[-1]Si*4(<:O>:Si-O-) (-[3]O) (<[5]O)}
end{document}