TRANSPORT

References: Bruck2014

Specifies the parameters for transport, sets parameters for the OMEN code, see also https://nano-tcad.ee.ethz.ch. [Edit on GitHub]

Subsections

• BEYN
• CONTACT
• PEXSI
• PRINT

Keywords

• COLZERO_THRESHOLD

• CONTACT_FILLING

• CSR_SCREENING

• CUTOUT

• DENSITY_MIXING

• ENERGY_INTERVAL

• EPS_DECAY

• EPS_EIGVAL_DEGEN

• EPS_FERMI

• EPS_LIMIT

• EPS_LIMIT_CC

• EPS_MU

• EPS_SINGULARITY_CURVATURES

• GPUS_PER_POINT

• INJECTION_METHOD

• LINEAR_SOLVER

• MATRIX_INVERSION_METHOD

• MIN_INTERVAL

• NUM_INTERVAL

• NUM_POLE

• N_KPOINTS

• N_POINTS_INV

• OBC_EQUILIBRIUM

• QT_FORMALISM

• REAL_AXIS_INTEGRATION_METHOD

• TASKS_PER_ENERGY_POINT

• TASKS_PER_POLE

• TEMPERATURE

• TRANSPORT_METHOD

Keyword descriptions

COLZERO_THRESHOLD: real = 1.00000000E-012

Usage: COLZERO_THRESHOLD

The smallest number that is not zero in the full diagonalization part. [Edit on GitHub]

CONTACT_FILLING: enum = BAND_STRUCTURE

Valid values:

• BAND_STRUCTURE Determine the Fermi levels from the band structure.

• DOS Determine the Fermi levels from the density of states.

Determination of the contact Fermi levels. Note that this keyword only works when the TRANSPORT_METHOD is specified as TRANSPORT. [Edit on GitHub]

CSR_SCREENING: logical = T

Lone keyword: T

Whether distance screening should be applied to improve sparsity of CSR matrices. [Edit on GitHub]

CUTOUT: integer[2] = 0 0

Usage: CUTOUT

The number of atoms at the beginning and the end of the structure where the density should not be changed. [Edit on GitHub]

DENSITY_MIXING: real = 1.00000000E+000

Usage: DENSITY_MIXING

Mixing parameter for a density mixing in OMEN. [Edit on GitHub]

ENERGY_INTERVAL: real = 1.00000000E-003

Usage: ENERGY_INTERVAL

Distance between energy points in eV. [Edit on GitHub]

EPS_DECAY: real = 1.00000000E-004

Usage: EPS_DECAY

The smallest imaginary part that a decaying eigenvalue may have not to be considered as propagating. [Edit on GitHub]

EPS_EIGVAL_DEGEN: real = 1.00000000E-006

Usage: EPS_EIGVAL_DEGEN

Filter for degenerate bands in the injection vector. [Edit on GitHub]

EPS_FERMI: real = 0.00000000E+000

Usage: EPS_FERMI

Cutoff for the tail of the Fermi function. [Edit on GitHub]

EPS_LIMIT: real = 1.00000000E-004

Usage: EPS_LIMIT

The smallest eigenvalue that is kept. [Edit on GitHub]

EPS_LIMIT_CC: real = 1.00000000E-006

Usage: EPS_LIMIT_CC

The smallest eigenvalue that is kept on the complex contour. [Edit on GitHub]

EPS_MU: real = 1.00000000E-006

Usage: EPS_MU

Accuracy to which the Fermi level should be determined. [Edit on GitHub]

EPS_SINGULARITY_CURVATURES: real = 1.00000000E-012

Usage: EPS_SINGULARITY_CURVATURES

Filter for degenerate bands in the bandstructure. [Edit on GitHub]

GPUS_PER_POINT: integer = 2

Usage: GPUS_PER_POINT

Number of GPUs per energy point for SplitSolve. Needs to be a power of two [Edit on GitHub]

INJECTION_METHOD: enum = BEYN

Usage: INJECTION_METHOD

Valid values:

• EVP Full eigenvalue solver.

• BEYN Beyn eigenvalue solver.

Method to solve the eigenvalue problem for the open boundary conditions. [Edit on GitHub]

LINEAR_SOLVER: enum = FULL

Usage: LINEAR_SOLVER

Valid values:

• SPLITSOLVE

• SUPERLU

• MUMPS

• FULL

• BANDED

• PARDISO

• UMFPACK

Preferred solver for solving the linear system of equations. [Edit on GitHub]

MATRIX_INVERSION_METHOD: enum = FULL

Usage: MATRIX_INVERSION_METHOD

Valid values:

• FULL

• PEXSI

• PARDISO

• RGF

Preferred matrix inversion method. [Edit on GitHub]

MIN_INTERVAL: real = 1.00000000E-004

Usage: MIN_INTERVAL

Smallest enery distance in energy vector. [Edit on GitHub]

NUM_INTERVAL: integer = 10

Usage: NUM_INTERVAL

Max number of energy points per small interval. [Edit on GitHub]

NUM_POLE: integer = 64

Usage: NUM_POLE

The number of terms in the PEXSI’s pole expansion method. [Edit on GitHub]

N_KPOINTS: integer = 64

Usage: N_KPOINTS

The number of k points for determination of the singularities. [Edit on GitHub]

N_POINTS_INV: integer = 64

Usage: N_POINTS_INV

Number of integration points for the sigma solver on the complex contour. [Edit on GitHub]

OBC_EQUILIBRIUM: logical = F

Lone keyword: T

Compute the equilibrium density with open boundary conditions. [Edit on GitHub]

QT_FORMALISM: enum = QTBM

Usage: QT_FORMALISM

Valid values:

• NEGF The non-equilibrium Green’s function formalism.

• QTBM The quantum transmitting boundary method / wave-function formalism.

Preferred quantum transport formalism to compute the current and density. [Edit on GitHub]

REAL_AXIS_INTEGRATION_METHOD: enum = GAUSS_CHEBYSHEV

Usage: REAL_AXIS_INTEGRATION_METHOD

Valid values:

• GAUSS_CHEBYSHEV Gauss-Chebyshev integration between singularity points.

• TRAPEZOIDAL_RULE Trapezoidal rule on the total range.

• READ Read integration points from a file (named E.dat).

Integration method for the real axis. [Edit on GitHub]

TASKS_PER_ENERGY_POINT: integer = 1

Usage: TASKS_PER_ENERGY_POINT

Number of tasks per energy point. The value should be a divisor of the total number of MPI ranks. [Edit on GitHub]

TASKS_PER_POLE: integer = 1

Usage: TASKS_PER_POLE

Number of tasks per pole in the pole expansion method. The value should be a divisor of the total number of MPI ranks. [Edit on GitHub]

TEMPERATURE: real = 3.00000000E+002 [K]

Usage: TEMPERATURE [K] 300.0

Temperature. [Edit on GitHub]

TRANSPORT_METHOD: enum = TRANSPORT

Usage: TRANSPORT_METHOD

Valid values:

• TRANSPORT self-consistent CP2K and OMEN transport calculations

• LOCAL_SCF CP2K valence Hamiltonian + OMEN self-consistent calculations on conduction electrons

• TRANSMISSION self-consistent transmission calculations without applied bias voltage

Preferred method for transport calculations. [Edit on GitHub]