SCF in LR calculations

Name LRConvAbsDens
Section Linear Response::SCF in LR calculations
Type float
Default 1e-5

The tolerance in the absolute variation of the density response, to determine if the SCF for linear response is converged. $\varepsilon = \int {\rm d}^3r \left| \rho^{out}(\bf r) -\rho^{inp}(\bf r) \right|$. A zero value means do not use this criterion.

Name LRConvRelDens
Section Linear Response::SCF in LR calculations
Type float
Default 0.0

The tolerance in the relative variation of the density response, to determine if the SCF for linear response is converged. $\varepsilon = \frac{1}{N_{\rm elec}}$ LRConvAbsDens. A zero value means do not use this criterion.

Name LRMaximumIter
Section Linear Response::SCF in LR calculations
Type integer
Default 200

The maximum number of SCF iterations to calculate response.

Name LRTolAdaptiveFactor
Section Linear Response::SCF in LR calculations
Type float
Default 0.1

This factor controls how much the tolerance is decreased during the self-consistency process. Smaller values mean that tolerance is decreased faster.

Name LRTolIterWindow
Section Linear Response::SCF in LR calculations
Type float
Default 10

Number of iterations necessary to reach the final tolerance.

Name LRTolScheme
Section Linear Response::SCF in LR calculations
Type integer
Default tol_adaptive

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.

Options:

• tol_fixed:
  The solver tolerance is fixed for all the iterations; this improves convergence but increases the computational cost
  
• tol_adaptive:
  The tolerance is increased according to the level of convergence of the SCF.
  
• tol_linear:
  The tolerance decreases linearly for the first LRTolIterWindow iterations.
  
• tol_exp:
  The tolerance decreases exponentially for the first LRTolIterWindow iterations.