Large chemfig diagram

\documentclass{article}

\special{papersize=20in,20in}
\setlength{\paperwidth}{20in}
\setlength{\paperheight}{20in}
\setlength{\textwidth}{20in}
\setlength{\textheight}{20in}

\usepackage{style}

\usepackage{tikz}
\usetikzlibrary{decorations}

\newcommand*{\bondboldwidth}{0.22832 em} %'Bold Width'
\newcommand*{\bondhashlength}{0.25737 em} % 'Hash Spacing'

\tikzset{
  bold bond/.style = {line width = \bondboldwidth},
  dash bond/.style =
  {dash pattern = on \bondhashlength off \bondhashlength},
  hash bond/.style =
  {
    dash pattern = on \bondwidth off \bondhashlength,
    line width   = \bondboldwidth
  },
  }

\tikzset{
  wavy bond/.style =
  {
    decorate,
    decoration =
    {
      complete sines,
      amplitude   = \bondboldwidth,
      post length = 0 pt,
      pre length  = 0 pt,
      % Use the atom spacing: saved
      segment length =
      \the\dimexpr\csname CF@atom@sep\endcsname/5\relax
    }
  }
}

\begin{document}

\definesubmol{sub_a}{
  *6(-=-
  (-O-[,2,,,bold bond]Fc)
  =-=)
}

\definesubmol{sub_b}{
  *6({-=-
    ({-
      ({
        -[::-60,1.2]-[::50,1.2]-[::-50]-[::60,1.2]Si(-[::60])(-[::120])-[::-30]-[::60]O-[::-34]!{sub_a}
      })
      ({
        -[::10]-[::-40]-[::70]-[::-60]Si(-[::-70])(-[::110])-[::50]-[::-60]O-[::30,1.1]!{sub_a}
      })
      ({
        -[::60,1.2]-[::-50,1.2]-[::50]-[::-60,1.2]Si(-[::-60])(-[::-120])-[::30]-[::-60]O-[::34]!{sub_a}
      })
    })
  =-=})
}

\definesubmol{sub_c}{
  *6({-=-
    ({-
      ({
        -[::-74,1.4]-[::50,1.3]-[::-50,1.4]-[::60,1.2]Si(-[::-90])(-[::90])-[::-30]-[::60]O-[::-30]!{sub_b}
      })
      ({
        -[::10]-[::-40]-[::70]-[::-60]Si(-[::-90])(-[::90])-[::50]-[::-60]O-[::30]!{sub_b}
      })
      ({
        -[::74,1.4]-[::-50,1.3]-[::50,1.4]-[::-60,1.2]Si(-[::-90])(-[::90])-[::30]-[::-60]O-[::30]!{sub_b}
      })
    })
    =-=
  })
}

\definesubmol{sub_d}{
  -[,1.5]
  ({
    -[::-99,1.4]-[::50,1.3]-[::-50,1.4]-[::60,1.2]Si(-[::-90])(-[::90])-[::-30]-[::60]O-[::-30]!{sub_c}
  })
  ({
    -[::10]-[::-40]-[::70]-[::-60]Si(-[::-90])(-[::90])-[::50]-[::-60]O-[::30]!{sub_c}
  })
  ({
    -[::99,1.4]-[::-50,1.3]-[::50,1.4]-[::-60,1.2]Si(-[::-90])(-[::90])-[::30]-[::-60]O-[::30]!{sub_c}
  })
}

\definesubmol{sub_e}{
  *6(
  =(-!{sub_d})-
  =(-!{sub_d})-
  =(-!{sub_d})-
  )
}

\chemfig{!{sub_e}}

\end{document}

%%% Local Variables:
%%% mode: latex
%%% TeX-master: t
%%% End: