Hi Everyone, I am currently working on an SCF (Self-Consistent Field) calculation for an organic system using the PBE0 functional. My primary objective is to obtain a more accurate estimation of the band gap. To achieve this, I need to determine the energy of the highest occupied level and the lowest unoccupied level. Due to this requirement, I am unable to use the smearing method and must set nbnd > nelec/2.
While this approach has been successful for most of the systems I have tested, I encountered an issue with a few specific systems. For these systems, the calculation continues to run for an unusually long time, and I notice that the program prints similar lines (provided below) after each iteration convergence. -------------------- estimated scf accuracy < 0.00000032 Ry convergence has been achieved in 1 iterations Using ACE for calculation of exact exchange ACE projected onto 50 (nbndproj) and applied to 50 (nbnd) bands ------------------- I would appreciate it if any of you could offer insights into what might be causing this problem or suggest potential solutions to resolve this convergence issue. Are there any parameters that can be tuned to achieve the convergence? Your expertise and advice would be of great help in overcoming this obstacle -- Rameswar Bhattacharjee Department of Chemistry Georgetown University Washington, DC 20057 _______________________________________________ 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 users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users