[Olog-hai]

Deuterium has the symbol “D”, not “H” (and certainly not a symbol resembling H-squared).

[EEGator]

I believe it can also be ²H.

[Pontiac]

Deuterium has the symbol “D”, not “H” (and certainly not a symbol resembling H-squared).

Deuterium can be denoted with the H. It is heavy isotope of hydrogen after all.

But the convention would be to have the superscript 2 before the H.

²H

Just as Carbon 14 is written as ¹⁴C