First-Principles Study of Dielectric Constant and Polarizability in Polydiacetylene Crystal

First principles calculations based on Density Functional Theory have been done on Polydiacetylene. Its triclinic unit cell has been simulated. Band gap in case of this material comes out to be 0.75eV. This value is in the range exhibited by semiconducting materials. Dielectric constant and Polarizability of the material have been computed. The value of dielectric constant comes out to be 50.6, 59.6 and 44.6 along X, Y and Z axes respectively and its average value comes out to be 51.6. Polarizability comes out to be 33.7 (Å)3, 34 (Å)3 and 33.4 (Å)3 along X, Y and Z axes respectively with an average value of 33.7 (Å)3.