Program settings

To configure the settings for a calculation using the DIALECT program, the file dialect.toml has to be created. You can either create the file yourself or you can run the program in a directory without the configuration file:

/your/path/to/DIALECT/dialect file.xyz

The dialect.toml will then be created using the standard values of the program. The settings of the file dialect.toml are explained in the following sections.

General settings

jobtype = "sp"
fmo = false
verbose = 0

jobtype

You can choose between "sp" for a DFTB or FMO-LC-DFTB calculation or "density" for the calculation of a given density in the AO basis on a grid.

fmo

If you want to do a FMO-DFTB calculation, set fmo=true.

verbose

Concerns the verbosity of the output. Values from -2 to 2 are possible. Higher values result in a much more detailed output.

[mol] config

[mol]
charge = 0
multiplicity = 1

You can change the charge and the multiplicity of the molecule. But at this point in time, the program only supports closed shell configurations!

[scf] config

The convergence settings of the self-consistent charge (SCC) routine are defined here.

[scf]
scf_max_cycles = 250
scf_charge_conv = 0.00001
scf_energy_conv = 0.00001

scf_max_cycles

Maximum number of iterations for the SCC routine

scf_charge_conv

Convergence criterium of the SCC routine. It concerns the charge difference to the previous iteration.

scf_energy_conv

Convergence criterium of the SCC routine. It concerns the energy difference to the previous iteration.

[lc] config

Here, you can turn the long-rang correction on and set the long-range radius. Be aware that a FMO calculation only works with an activated long-range correction.

[lc]
long_range_correction = true
long_range_radius = 3.03

[excited] config

[excited]
calculate_excited_states = false
nstates = 10
davidson_iterations = 100
davidson_subspace_multiplier = 10

calculate_excited_states

If you want to calculate the excited states in a standard DFTB or FMO-DFTB caluculation, set this option to true.

nstates

Number of requested excites states.

davidson_iterations

Maximum number of iterations for the Davidson routine.

davidson_subspace_multiplier

Maximum scaling factor of the dimension for the guess vectors of the Davidson algorithm. It is multiplied with the number of requested excited states.

[tda_dftb] config

[tda_dftb]
restrict_active_orbitals = false
active_orbital_threshold = 0.2
save_transition_densities = false
states_to_analyse = [0, 1]

Settings concerning a normal TDA-TDDFTB calculation

restrict_active_orbitals

Reduce the number of occupied and virtual orbitals involved during the TDDFTB calulation.

active_orbital_threshold

Set the fraction of the full orbital space

save_transition_densities

Save the transition density matrix in AO basis for the requested excited states.

states_to_analyse

Select the states for which you want to calculate and save the transition density matrices.

[slater_koster] config

[slater_koster]
use_external_skf = false
skf_directory = " "

use_external_skf

Use Slater-Koster parameters from external source.

skf_directory

Specify the path to the SKF-files. "/path/to/SKF/"

[parallelization] config

[parallelization]
number_of_cores = 1

number_of_cores

Use the specified number of processor cores for the calculation. It only affects a FMO-DFTB calculation

[fmo_lc_tddftb] config

[fmo_lc_tddftb]
restrict_active_space = true
active_space_threshold_le = 0.0001
active_space_threshold_ct = 0.0001
n_le = 2
n_ct = 1
calculate_all_states = false
calculate_ntos = false
calculate_transition_densities = false
calculate_particle_hole_densities = false
states_to_analyse = [0, 1]

Settings for the excited state calculation using the FMO-LC-TDDFTB method

restrict_active_space

Calculate only relevant transitions between orbitals for the exchange part of the couplings between the LE and CT states.

active_space_treshold_le

Threshold for the one electron transition density matrices of the LE states.

active_space_treshold_ct

Threshold for the one electron transition density matrices of the CT states.

n_le

Number of locally excited states for each monomer fragment.

n_ct

Number of charge-transfer states for each pair fragment.

calculate_all_states

Do a full diagonalization of the excitonic Hamiltonian instead of the Davidson routine.

calculate_ntos

Calculate the natural transition orbitals for the specified excited states. They will be stored as molden files, which can be viewed in jmol.

calculate_transition_densities

Calculate the transition density matrices in AO basis for the specified excited states. They will be stored as binary numpy files.

calculate_particle_hole_densities

Calculate the particle and hole densities for the specified excited states. They will be stored as binary numpy files.

states_to_analyze

List of the excited states for which the ntos or densities will be calculated.

[density] config

[density]
path_to_density = " "
points_per_bohr = 2.0
threshold = 0.0001
use_block_implementation = true
n_blocks = 1

Settings regarding the calculation of a density in AO basis on the grid, which will be stored as a cube file.

dialect manual