# What is the meaning of a decimal in a subscript in a chemical formulas? [duplicate]

What is the meaning of a decimal in a subscript in a chemical formulas?

I came across the fractional subscripts in a publication,[1] for example:

We introduce oxygen into a ferromagnetic metallic glass to form a $$\ce{Co_{28.6}Fe_{12.4}Ta_{4.3}B_{8.7}O46}$$ magnetic semiconductor with a Curie temperature above $$\pu{600 K}$$. "

How do I interpret these numbers?

### References:

1. Liu, W.; Zhang, H.; Shi, J.; Wang, Z.; Song, C.; Wang, X.; Lu, S.; Zhou, X.; Gu, L.; Louzguine-luzgin, D. V.; Chen, M.; Yao, K.; Chen, N. A room-temperature magnetic semiconductor from a ferromagnetic metallic glass. Nat. Commun. 2016, 7, 13497 DOI: 10.1038/ncomms13497.
• also, from the paper "In this way, a single metal oxide Co28.6Fe12.4Ta4.3B8.7O46 (in atomic percentage) is produced " Dec 10 '16 at 20:58
• Permeakra - you are assuming the atons are covalently bonded to eachother. It is possible to have atoms randomly dispersed within a material. A perfect example are clays which usually have non-stoichiometric subscripts in their chemical formulas. It's not 0.5 atoms, it would be 0.5% molarity for that atom within a sample. Dec 10 '16 at 21:13
• @EframGoldberg and for that matter, the atoms in the clays are by no means inserted randomly. They are located in some specific positions, even if not all of them are occupied. Dec 10 '16 at 21:48
• @Permeakra obviously placement can't violate physical laws, but if a unit cell requires a cation, then cationic species can be inserted randomly into that position. I quote from USGS "Other Group IA or Group IIA cations may also be randomly distributed over water-molecule sites" or "In K(UO,AsO,) .3H,O, one potassium ion and three H,O molecules are distributed randomly over four water-molecule sites" In fact when modeling clay structures, random distributions are often used. Dec 13 '16 at 18:21

In the case of complex glasses such as $$\ce{Co_{28.6}Fe_{12.4}Ta_{4.3}B_{8.7}O46}$$, Instead of normalizing the subscripts to have integer subscripts they normalized them by molar percent such that the sum of subscripts is $$100\%$$
($$28.6+12.4+4.3+8.7+46=100$$)