As we can see, my supernova's spectrum have 4 picks. And according to my calculation, the first pick has 11.5% of Oxygen VII. The second pick has 9.5% of Ne IX, and including Ne X. The pick number three has 6.1% of Magnesium. The last one only has 2.8% of Silicium.
The scientist say that is composed by Oxygen and Silicium (depending the light curve)