In my book there's a question:
Does $\ce{H2}$ shows allotropy ? Enlist its allotropes and their application?
I pondered over different way Hydrogen can be arranged(I don't know but I have weak intuition that hydrogen bonding can play a role) but to no resolute
After awhile I googled to find different answers :Some are enlisting NSIs of hydrogen as allotrope
So can NSI(s) of an element can be considered allotrope ?
If yes then how Nuclear Spin Isomer can affect their physical form/structures?
*Wikipedia also doesn't enlist any allotrope of $\ce{H2}$ as such. https://en.wikipedia.org/wiki/Allotropy