| Molecular weights {GCDkit} | R Documentation | 
Calculates molecular weights for simple oxide formula(e).
molecularWeight(formula)
| formula | a character vector with formula(e) of the oxide(s). | 
So far only simple oxide formulae in form of AxOy (where x, y are optional indexes)
can be handled. The atomic weights are stored in a file MW.data in the main directory. 
The atomic weights come from official CIAAW  web site 
https://www.ciaaw.org.  
A list with items:
| MW | molecular weight(s) | 
| x.atoms | number(s) of atoms in the formula | 
| x.oxygen | number(s) of oxygens | 
Vojtěch Janoušek, vojtech.janousek@geology.cz and Vojtěch Erban, erban@sopky.cz
Commission on Isotopic Abundances and Atomic Weights (CIAAW) of the International Union of Pure and Applied Chemistry. Accessed on January 8, 2016, at https://www.ciaaw.org
    molecularWeight("SiO2")
    molecularWeight("SiO2")[[1]]
    MW["SiO2"]
    MW[major]
    mw["Si"]
    oxides<-c("SiO2","TiO2","Al2O3","Fe2O3","FeO")
    sapply(oxides,molecularWeight)