Section Linear Response::SCF in LR calculations
The scheme used to adjust the tolerance of the solver during the SCF iteration. For kdotp and magnetic em_resp modes, or whenever HamiltonianVariation = V_ext_only, the scheme is set to tol_fixed, and this variable is ignored.
The solver tolerance is fixed for all the iterations; this
improves convergence but increases the computational cost
The tolerance is increased according to the level of
convergence of the SCF.
The tolerance decreases linearly for the first LRTolIterWindow iterations.
The tolerance decreases exponentially for the first LRTolIterWindow iterations.
hamiltonian/scf_tol.F90 : 153
call parse_variable(namespace, 'LRTolScheme', SCF_TOL_ADAPTIVE, this%scheme)