Does anybody know if the Molecular Hydrogen theory of dark matter is still considered valid?

Question

In (very) crude terms Atomic Hydrogen (H1) is easy to detect and very abundant. Molecular Hydrogen (H2) is hard to detect and would account for the "matter deficiency" in universe modelling. Sounds very plausible to me, but it does not seem to a lot of support.

http://www.newtonphysics.on.ca/hydrogen/index.html

Answer 1

The ratio of molecular hydrogen to carbon monoxide is fairly constant at about 30000:1, and carbon monoxide is detectable.  There is nowhere near enough carbon monoxide detected to account for the Dark Matter, and even so, it's not distributed at all the same.  Dark Matter is even less concentrated to galaxies than are stars, and molecular hydrogen is much more concentrated to galaxies than are stars.  If there were molecular hydrogen without carbon monoxide that were distributed like Dark Matter is distributed, there would be large, extragalactic regions where the molecular hydrogen wouid be shocked by more than 100 km/s, and that would result in visible emission at 2.2 microns.  Such emission is not seen.  The distribution of Dark Matter shows that it does not collide with itself or with any ordinary matter.

Furthermore, Big Bang nucleosynthesis (synthesis of He, Li, and some B in the first 1000 seconds of the Big Bang) only makes sense if the Dark Matter is not baryonic.