Hello again, The system is getting stuck in a local minimum, it seems. How to bring the system to global minimum?
Any help is highly appreciated. Thanks in advance. Sunetra. On 25 June 2018 at 10:01, Sunetra Das <sunetra.das...@gmail.com> wrote: > Hello experts, > > I have been trying to optimize a 2D structure with 3 atoms in the unit > cell. I am using CG by varying the cell dimensions. I have optimized the > k-points and mesh cutoff. But no matter how many times I try to relax the > structure, it is giving a negative phonon frequency at the gamma point. The > structure is experimentally achieved structure with available .cif file. > The cell dimensions achieved after relaxation are the same as the > experimentally achieved one, with less than 2% deviation, and theoretical > work publications show that the structure should come out to a stable one > with no negative frequencies. > > Where can be the issue? I am using fully relativistic .psf files and > spin-polarization is on. Can basis set optimization be an issue? > Help please. > > Regards, > Sunetra Das. >
