This example equation (by
Frank Kampas) was created using Ctrl+_ to get into Subscript position, right arrow to get back out and Equilibrium symbol entered as Esc equi Esc. Just copy and paste this linear 2D string code, to see the formatted display result in a Mathematica Notebook.
"3\!\(\*SubscriptBox[\(Zn\), \(1\)]\) + 8\!\(\*SubscriptBox[\(H\), \
\(1\)]\)\!\(\*SubscriptBox[\(N\), \(1\)]\)\!\(\*SubscriptBox[\(O\), \
\(3\)]\) \[Equilibrium] 3\!\(\*SubscriptBox[\(Zn\), \
\(1\)]\)\!\(\*SubscriptBox[\(N\), \(2\)]\)\!\(\*SubscriptBox[\(O\), \
\(6\)]\) + \!\(\*SubscriptBox[\(N\), \
\(1\)]\)\!\(\*SubscriptBox[\(O\), \(1\)]\) + \
4\!\(\*SubscriptBox[\(H\), \(2\)]\)\!\(\*SubscriptBox[\(O\), \(1\)]\)"
