Dear Dr. Timrov, Thanks for your answer. I was trying to perform the calculation with Si as a test.. Now I'm trying to perform the calculation with the crystal I'll work with... I want to reproduce the paper "DFT calculations of the structural, electronic, optical and vibrational properties of anhydrous orthorhombic L-threonine crystals" but with another amino acid (4 molecules in the crystal). My first question is, in this situation, should I create a supercell? I applied the same parameters in the SCF (gamma k-points), Lanczos, and Spectrum. In the end, I got the plot_S and plot_chi files. In the former, it has the column omega(Ev) and Oscillator strength. In the second, there's a kind of matrix: \hbar \omega(eV) Re(chi) (e^2*a_0^2/eV) Im(chi) (e^2*a_0^2/eV) chi_1_1= 0.000000000000000E+00 0.251513541607848E+02 -.000000000000000E+00 chi_2_1= 0.000000000000000E+00 0.289682796308743E-01 -.000000000000000E+00 chi_3_1= 0.000000000000000E+00 -.627424728613613E+01 0.000000000000000E+00 chi_1_2= 0.000000000000000E+00 0.287160382756907E-01 -.000000000000000E+00 chi_2_2= 0.000000000000000E+00 0.316761800714172E+02 -.000000000000000E+00 chi_3_2= 0.000000000000000E+00 -.136008122822626E-01 0.000000000000000E+00 chi_1_3= 0.000000000000000E+00 -.627868400613771E+01 0.000000000000000E+00 chi_2_3= 0.000000000000000E+00 -.132116766101710E-01 0.000000000000000E+00 chi_3_3= 0.000000000000000E+00 0.250771241870414E+02 -.000000000000000E+00 I believe the Real and Imaginary parts of the Dielectric function are columns 3 and 4. How can I use these data to plot a graph for the different directions ([001] [010][100])?
_______________________________________________ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
