KUBO_TRANSPORT
References: Kühne2020a
Finite-volume Kubo-Greenwood transport coefficients from the converged Quickstep Hamiltonian, overlap matrix, and atomic geometry. For one- and two-dimensional cells, transport is projected onto the periodic subspace and normalized by the periodic length or area. [Edit on GitHub]
Keywords
Keyword descriptions
SECTION_PARAMETERS
Type: logical
Default: F
Lone keyword: T
Description: Controls the activation of the Kubo transport calculation. [Edit on GitHub]
CURRENT_OPERATOR
Type: enum
Default: ATOM_EMBEDDING
Description: ATOM_EMBEDDING retains the finite-volume atom-coordinate model. PROJECTED_AO uses analytic AO positions and the metric-aware commutator HS^-1X-XS^-1H, with complex spinors when SOC is enabled. PROJECTED_AO requires PERIODIC NONE and GPW/GAPW. This is the current of the projected AO Hamiltonian. BLOCH evaluates analytic Hamiltonian/overlap k derivatives and the AO connection on a full MP_GRID, with optional SOC and intraband terms. BLOCH requires a periodic GPW/GAPW calculation. [Edit on GitHub]
Valid values:
ATOM_EMBEDDINGPROJECTED_AOBLOCH
DISSIPATION
Type: real
Default: 3.00000000E+002 [K]
Usage: DISSIPATION 300.0
Description: Dissipation/broadening parameter in the finite-temperature Kubo formula. [Edit on GitHub]
ENERGY_RANGE
Type: real[2]
Default: 0.00000000E+000 0.00000000E+000 [hartree]
Usage: ENERGY_RANGE -0.5 0.5
Description: Absolute chemical-potential range. The default 0 0 uses the full eigenvalue range of the finite-volume Hamiltonian. [Edit on GitHub]
EPS_SYMMETRY
Type: real
Default: 1.00000000E-006
Description: Geometric tolerance for BLOCH property symmetry detection. [Edit on GitHub]
EPS_SYMMETRY_OPERATORS
Type: real
Default: 1.00000000E-008
Description: Tolerance for target metric, energy-scaled Hamiltonian, and current covariance checks. The current error is scaled by max(1,|J|) in atomic units. [Edit on GitHub]
HALL_RESPONSE
Type: logical
Default: F
Description: Include the antisymmetric DC charge response in the conductivity tensor and print its three independent components separately. Requires PROJECTED_AO or BLOCH. Uses the same positive scalar DISSIPATION; does not add magnetic order, an applied magnetic field, spin Hall currents, or microscopic scattering mechanisms. [Edit on GitHub]
MAX_AO
Type: integer
Default: 512
Description: Safety limit on scalar AO dimension for PROJECTED_AO or BLOCH. Dense spinor matrices have dimension 2*NAO when SOC is enabled. [Edit on GitHub]
MAX_MEMORY_MB
Type: integer
Default: 1024
Description: Safety bound in MiB on replicated BLOCH array storage per MPI rank. Excludes CP2K/DBCSR environment and library workspace. [Edit on GitHub]
METHOD
Type: string
Default: DIAGONALIZATION
Usage: METHOD DIAGONALIZATION
Description: Transport algorithm. DIAGONALIZATION evaluates the finite-volume Kubo-Greenwood expression from the explicit spectrum. TD and CHEBYSHEV are reserved for future diagonalization-free implementations. [Edit on GitHub]
MP_GRID
Type: integer[3]
Default: 1 1 1
Description: Full Gamma-centered property mesh for CURRENT_OPERATOR BLOCH. Independent of SCF sampling and symmetry reduction, at the frozen SCF potential. Nonperiodic directions must be one. [Edit on GitHub]
NEUTRAL_GRID
Type: integer
Default: 10000
Usage: NEUTRAL_GRID 10000
Description: Number of grid points used to locate the neutral chemical potential. [Edit on GitHub]
NEUTRAL_MU
Type: real
Default: [hartree]
Usage: NEUTRAL_MU 0.245467619658419
Description: Optional fixed neutral chemical potential. If omitted, the neutral point is found from the eigenvalue spectrum and total electron count. [Edit on GitHub]
N_MU
Type: integer
Default: 200
Usage: N_MU 200
Description: Number of chemical-potential grid points. [Edit on GitHub]
SOC
Type: logical
Default: F
Description: Add GTH-SOC in the complete AO spinor space after a restricted SCF. Requires CURRENT_OPERATOR PROJECTED_AO or BLOCH and SOC pseudopotential parameters. Does not perform self-consistent noncollinear DFT. A time-reversal-symmetric Hamiltonian has zero net charge Hall response. [Edit on GitHub]
SYMMETRY
Type: logical
Default: F
Description: Reconstruct equivalent BLOCH property eigenframes from independent irreducible points. Includes atom/AO, cell-image and physical SOC spin transformations. Every reconstructed frame is checked against the target H/S and current; an inconsistent frozen SCF potential aborts instead of silently changing the response. [Edit on GitHub]
SYMMETRY_BACKEND
Type: enum
Default: K290
Description: Backend for the independent BLOCH property symmetry mesh. [Edit on GitHub]
Valid values:
K290SPGLIB
TEMPERATURE
Type: real
Default: 1.00000000E+000 [K]
Usage: TEMPERATURE 1.0
Description: Electronic temperature used in the Fermi operator. [Edit on GitHub]