"Implementation of imaginary time dependent density functional theory to periodic and noncollinear systems"

Recently an alternative to the SCF method for calculating the DFT electronic ground state was proposed that evolves the DFT wave function in imaginary time [1]. One benefit of this new method is that the DFT wave function is guaranteed to lower its energy and eventually reach the ground state with a sufficiently small time step. This avoids the problems in SCF that hinder convergence such as charge sloshing, which can necessitate fractional level filling. We extend imaginary time dependent density functional theory to periodic systems using a modification of the DFT package Quantum ESPRESSO, with the option of noncollinear and DFT+U calculations. We discuss some of the technical aspects of this as well as example systems which converge with this modification but have difficulty with standard implementations of SCF.

[1] arXiv:1903.00766v2 [physics.comp-ph] (2019)