How can I get the weight percentages of each species in the compounds

In material project I am trying to get all data containing Li-Mn-O and their band gap. I am trying to examine the relation between weight percentage and bandgap. However, I can not see the information about the weight percent of each element in the compound on material project. For example: in Li2MnO3, the weight percent of Li is 0.1183 and one of Mn is 0.47028. I can google and calculate it but, I need the data for all the cases of compound I get from material project to do algo to find the compound with the highest bandgap depending on the weight percent. Therefore, I need the feed-in data for my computer.
Anyone know about it or have any suggestion.

Hi @dolong2110

We typically don’t deal in weight percents for species, nor do we think about relating that to a property. That being said, this is very easy if you use our python library pymatgen. There is a Composition class which has a get_wt_fraction method that takes an element.