TDDeltaStrengthMode
TDDeltaStrengthMode
Section Time-Dependent::Response
Type integer
Default kick_density
When calculating the density response via real-time propagation,
one needs to perform an initial kick on the KS system, at
time zero. Depending on what kind of response property one wants to obtain,
this kick may be done in several modes. For use to calculate triplet excitations,
see MJT Oliveira, A Castro, MAL Marques, and A Rubio, J. Nanoscience and Nanotechnology 8, 3392 (2008).
Options:
- kick_density:
The total density of the system is perturbed. This mode is appropriate for
electric dipole response, as for optical absorption.
- kick_spin:
The individual spin densities are perturbed oppositely. Note that this mode
is only possible if the run is done in spin-polarized mode, or with spinors.
This mode is appropriate for the paramagnetic dipole response, which can couple
to triplet excitations.
- kick_spin_and_density:
A combination of the two above. Note that this mode
is only possible if the run is done in spin-polarized mode, or with spinors.
This mode is intended for use with symmetries to obtain both of the responses
at once, at described in the reference above.
- kick_magnon:
Rotates the magnetization. Only works for spinors.
Can be used in a supercell or my making use of the generalized Bloch theorem.
In the later case (see SpiralBoundaryConditions) spin-orbit coupling cannot be used.