27592
In this paper , the surface structures of two very different bioglass compositions , namely 45S5 ( 46 . 1 SiO2 , 24 . 4 Na2O , 26 . 9 CaO , and 2 . 6 P2O5 mol % ) and 77S ( 80 . 0 SiO2 , 16 . 0 CaO , and 4 . 0 P2O5 mol % ) , have been investigated by means of periodic DFT calculations based on a PBE functional and localized Gaussian basis set as encoded in the CRYSTAL code .
 Chemical: SiO2; Chemical: Na2O; Chemical: CaO; Chemical: P2O5; Chemical: SiO2; Chemical: CaO; Chemical: P2O5
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: SiO2; Chemical: Na2O; Chemical: CaO; Chemical: P2O5; Chemical: SiO2; Chemical: CaO; Chemical: P2O5