Electron
Options for the electronic subsystem solver.
solver#
Parameters concerning the system solver.
obc#
Parameters concerning the open boundary conditions.
eta_obc#
Small imaginary value to add to the energy when computing the OBCs.
Including this small broadening can help stabilize the convergence of the iterative sancho-rubio OBC solver near van Hove singularities.
eta#
Small imaginary value to add to the energy when computing the Green's functions.
left_contact#
Configuration for the left contact.
This must be provided for any "negf" simulation.
Note
In "wf" simulations, the left and right contacts are not used.
right_contact#
Configuration for the right contact.
This must be provided for any "negf" simulation.
Note
In "wf" simulations, the left and right contacts are not used.
band_edge_tracking#
Whether to track the band edges during the SCBA iterations.
This is setting is only useful if the considered interactions result in energy renormalization in the electronic subsystem, which is primarily the screened Coulomb interaction.
If set to True, the band edges are tracked during the SCBA
iterations by computing the eigenvalues of the Hamiltonian
renormalized with the current self-energy.
The Fermi levels are then set to be a fixed distance from the band edges, which is determined by the initial Fermi level and band edges. For example, if the initial Fermi level is 0.5 eV above the conduction band edge, the Fermi level is always set to be 0.5 eV above the conduction band edge during all SCBA iterations.
energy_window_min#
The minimum energy of the energy grid used for electronic quantities.
energy_window_max#
The maximum energy of the energy grid used for electronic quantities.
energy_window_num#
The number of energy points in the energy grid used for electronic quantities.
Either energy_window_num or
energy_window_num_per_rank can be
set to determine the total number of energy points.
energy_window_num_per_rank#
The number of energy points per rank in the energy grid used for electronic quantities.
Either energy_window_num or
energy_window_num_per_rank) can be set to determine the total
number of energy points.
flatband#
Whether the system is in flatband conditions.
If not set, it is automatically determined from the left and right Fermi levels. If the Fermi levels are equal, it is assumed to be in flatband conditions.
dos_peak_limit#
The maximum derivative of the density of states (DOS) with respect to energy.
At energy points where the DOS derivative exceeds this value, the electronic quantities are set to zero to stabilize the convergence of the SCBA iterations.
This is especially a problem during the first few SCBA iterations when the self-energies are not yet fully developed and can lead to very sharp features in the DOS.
filtering_iteration_limit#
The maximum number of SCBA iterations during which the DOS peak filtering is applied.
This is because the DOS peak filtering is mainly needed during the first few SCBA iterations when the self-energies are not yet fully developed and can lead to very sharp features in the DOS.
max_batch_size#
The maximum number of energies to batch together in the solution of the electronic subsystem.
This controls how many energies are treated together when computing boundary conditions and electron Green's functions. If not set, all energies are computed at once.
This can help mitigate memory bottlenecks.