THE INFLUENCE OF PHENYL RINGS ON THE COHESIVE ENERGY AND THE DENSITY OF STATE OF TETRACENE MOLECULE

In this work, we calculate the average cohesive energy, total energy and the density of state for different number of phenyl groups, one and four rings, on different position of tetracene molecule by using density functional theory with SIESTA code. By comparing the value of them for pure tetracene and its derivatives, we found that adding the number of phenyl rings increase the magnitude of average cohesive energy and decrease the value of HUMO-LUMO gap. On the other hand, by moving the phenyl groups from the center of the tetracene molecule to the edge of it, the average cohesive energy was decreased but has not important effect on the HUMO-LUMO gap.