For a particular system: By comparing the DFT result to the one obtained with an accurate method (e.g., experiment, BSE, GW, hybrid) if available. If no exp/BSE/GW/hybrid result is available, search for information in the literature about the accuracy of the DFT method for systems similar to yours.
In general: Read the literature. From: Wien <wien-boun...@zeus.theochem.tuwien.ac.at> on behalf of Mohad Abbasnejad <mohaddeseh.abbasne...@gmail.com> Sent: Saturday, October 17, 2020 1:09 PM To: A Mailing list for WIEN2k users Subject: [Wien] Regarding calculation of optical properties Dear experts, Actually, one of the challenging problems in calculating the optical properties by DFT method (using PBE or mbJ) is its accuracy. So, how is it possible to demonstrate the reliability of the results obtained by this method? Any comments would be appreciated. Regards, Mohaddeseh _______________________________________________ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html