Theoretical Studies of Atomic Structure and Electron Properties of Tetracene

The first-principle calculation is used to study the structure model of tetracene molecule.The total density of state of tetracene shows six resonances.The electron structure of the whole molecule is obtained by DV-Xα calculation,and six resonances are shown in the results.Two theoretical calculations are in accord with each other,and they are both agreement with the experiment data.The experiment spectra only shows five features,but in the two theoretical calculations we both find there is one weak feature lying in between 1 peak and 2 peak,which is attributed to the tetracene molecule,not Ag.Finally the DV-Xα calculation explains the physical origins of features in the UPS spectra.