Complex sentence: The building is similar to the Byzantine Church of Saints Sergius and Bacchus and the later Chrysotriklinos, or throne hall and palace church of Constantinople, and it would be used as the model for Charlemagne's palace chapel at Aix-la-Chapelle.
Split into simpler sentences: The building is similar to the earlier Church of Saints Sergius and Bacchus and to the later Chrysotriklinos, or throne hall and palace church of Constantinople. It would be used as the model for Charlemagne's palace chapel at Aix-la-Chapelle.