14885
Electronic structure calculations based on density functional theory show that the bandgap transition results from the excitation of electrons at the band edges between filled Cu ( I ) 3d (1) 0 - orbitals and empty Nb ( V ) 4d 0 - orbitals , respectively .
 Chemical: Cu ( I ); Chemical: Nb ( V )
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: Cu ( I ); Chemical: Nb ( V )