Energy Band Valence Density of States

With the full occupancy of the p-orbit of oxygen, the sp orbits of the 0 hybridize, which brings about four additional DOS features, as illustrated in Fig. 2.3b  

The bonding states are close to the originally occupied 2p level of the isolated oxygen. 

Non-bonding lone pairs and antibonding dipoles are generated in a reaction with -orbit hybridization being involved, such as in the processes of 

Usually, the parts in the brackets are omitted in formulating reactions because they share no charges with the electron acceptors. Under UV irradiation or thermal excitation, the hybrid ip -orbit can be dehybridized, and the lone pairs and dipoles are removed accordingly. 

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