Parameters for calculating densityOfScatteringStates¶
A scattering state is an eigen-states of the open device structure. A density of scattering states (DOSS) can be defined to indicate the number of scattering states at some energy. Parameters here are for calculating the DOSS.
calculation.densityOfScatteringStates.leadIndexOfIncomingStates¶
key word |
: |
calculation.densityOfScatteringStates.leadIndexOfIncomingStates |
possible values |
: |
an integer |
default value |
: |
no default value |
description |
: |
lead index. The density of scattering states whose |
incoming states are from the given lead will be calculated. |
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an example |
: |
calculation.densityOfScatteringStates … |
.leadIndexOfIncomingStates = 1 |
calculation.densityOfScatteringStates.isResolved¶
key word |
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calculation.densityOfScatteringStates.isResolved |
possible values |
: |
true or false |
default value |
: |
false |
description |
: |
If true, the density of scattering states (doss) is |
resolved in k-space, instead of integrated over the |
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Brillouin zone. |
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an example |
: |
calculation.densityOfScatteringStates.isResolved = 0 |
calculation.densityOfScatteringStates.kSpaceGridNumber¶
key word |
: |
calculation.densityOfScatteringStates.kSpaceGridNumber |
possible values |
: |
3\(\times\)1 integer array |
default value |
: |
the value of calculation.k_spacegrids.number which is |
used in the Hamiltonian calculation, or [1 1 1] if an |
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user provided Hamiltonian is used. |
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description |
: |
the small k-space grid number in each direction which, |
together with kSpaceGridShift, are used to produce the |
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parameter kSpacePoints. |
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an example |
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calculation.densityOfScatteringStates … |
.kSpaceGridNumber = [10 10 10] |
calculation.densityOfScatteringStates.kSpaceGridShift¶
key word |
: |
calculation.densityOfScatteringStates.kSpaceGridShift |
possible values |
: |
3\(\times\)1 or 1\(\times\)3 array, [s\(_1\), s\(_2\), s\(_3\)], each s\(_i\) is a |
double number between 0 and 1. |
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default value |
: |
if the densityOfScatteringStates.kSpaceGridNumber is |
given, or if an user-provided Hamiltonian is used, the |
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default value is [0 0 0]; otherwise the default value is |
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the value of calculation.k_spacegrids.shift which was |
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used in the Hamiltonian calculation. |
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description |
: |
k-space grid point shift. While all s\(_i\) are set to 0, |
the Gamma point is always among the k-space grid points |
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being generated; otherwise, the k-space grid points will |
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be shifted s\(_1\), s\(_2\), and s\(_3\) grid lengths along their |
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grid vector directions, respectively. |
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an example |
: |
calculation.densityOfScatteringStates … |
.kSpaceGridShift = [1/2 1/2 1/2] |
calculation.densityOfScatteringStates.kSpacePoints¶
key word |
: |
calculation.densityOfScatteringStates.kSpacePoints |
possible values |
: |
3\(\times\)n double array |
default value |
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defined in the k-point file if the file is given by |
the parameter densityOfScatteringStates.kPointFile, or |
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produced by the parameters |
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densityOfScatteringStates.kSpaceGridNumber and |
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densityOfScatteringStates.kSpaceGridShift. |
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description |
: |
the fractional coordinates of n (transverse) wave vectors |
which are used in the k-space integration, or at which |
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the resolved dos is calculated. |
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an example |
: |
calculation.densityOfScatteringStates.kSpacePoints … |
= [0 0 0] |
calculation.densityOfScatteringStates.kPointWeights¶
key word |
: |
calculation.densityOfScatteringStates.kPointWeights |
possible values |
: |
1\(\times\)n double array |
default value |
: |
defined in the k-point file if the corresponding |
parameter densityOfScatteringStates.kSpacePoints is |
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using the k-values in the same file. Otherwise, equally |
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weighted or calculated by nanodcal. |
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description |
: |
the weights of the k-space points in the k-space |
integration. |
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an example |
: |
calculation.densityOfScatteringStates.kPointWeights … |
= [1/2 1/3 1/6] |
calculation.densityOfScatteringStates.kPointFile¶
key word |
: |
calculation.densityOfScatteringStates.kPointFile |
possible values |
: |
a file name |
default value |
: |
no default value |
description |
: |
the name of a file which contains the coordinates of |
k-space points and their corresponding weights. |
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A k-point file with n k-points has (n+1) lines: one line |
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of headers and n lines of the values of the n k-points. |
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The headers are: |
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number : the sequential number of the k-point |
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k1, k2, k3 : fractional coordinates of the k-point |
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divisor : used to modify k1, k2, and k3 so that the |
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real fractional coordinates are |
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k1/divisor, k2/divisor, k3/divisor |
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weight : relative weights of the k-points for the |
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k-space integration. It is normalized |
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so that sum(weight) = 1. |
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where the headers number, divisor, and weight are |
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optional. |
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an example |
: |
calculation.densityOfScatteringStates.kPointFile … |
= k-points.dat |
calculation.densityOfScatteringStates.isIntegrated¶
key word |
: |
calculation.densityOfScatteringStates.isIntegrated |
possible values |
: |
true or false |
default value |
: |
false |
description |
: |
If true, the density of the scattering states (dos) is |
integrated over the given energy range, instead of being |
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expressed as a function of energy. |
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an example |
: |
calculation.densityOfScatteringStates.isIntegrated = 0 |
calculation.densityOfScatteringStates.energyRange¶
key word |
: |
calculation.densityOfScatteringStates.energyRange |
possible values |
: |
a 2\(\times\)1 double array |
default value |
: |
no default value |
description |
: |
When isIntegrated is true, this parameter defines the |
energy range over which DOS is integrated. |
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When isIntegrated is false, this parameter is used, |
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together with numberOfEnergyPoints, to define the |
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parameter energyPoints. |
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Note that its values are measured from the chemical |
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potential of the lead with zero applied voltage. |
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an example |
: |
calculation.densityOfScatteringStates.energyRange = [-10,10] |
calculation.densityOfScatteringStates.numberOfEnergyPoints¶
key word |
: |
calculation.densityOfScatteringStates.numberOfEnergyPoints |
possible values |
: |
an integer number |
default value |
: |
determined by parameters energyRange and energyInterval. |
description |
: |
When isIntegrated is true, this parameter is used to |
perform the integration. |
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When isIntegrated is false, this parameter is used, |
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together with energyRange, to define the parameter |
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energyPoints. |
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an example |
: |
calculation.densityOfScatteringStates … |
.numberOfEnergyPoints = 100 |
calculation.densityOfScatteringStates.energyInterval¶
key word |
: |
calculation.densityOfScatteringStates.energyInterval |
possible values |
: |
a double number |
default value |
: |
5e-2 eV |
description |
: |
Energy interval used to determine the parameter |
numberOfEnergyPoints. |
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an example |
: |
calculation.densityOfScatteringStates.energyInterval = 1e-3 |
calculation.densityOfScatteringStates.energyPoints¶
key word |
: |
calculation.densityOfScatteringStates.energyPoints |
possible values |
: |
n\(\times\)1 double array with n an integer |
default value |
: |
Fermi energy or chemical potentials of all the leads when |
energyRange is not given; otherwise, determined by |
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energyRange and numberOfEnergyPoints. |
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description |
: |
when isIntegrated is true, this parameter is used, |
together with energyPointWeights, to perform the |
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energy integration. |
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When isIntegrated is false, the density of the |
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scattering states will be calculated at those energy |
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points. |
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Note that its values are measured from the chemical |
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potential of the lead with zero bias voltage. |
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an example |
: |
calculation.densityOfScatteringStates.energyPoints = 0 |
calculation.densityOfScatteringStates.energyPointWeights¶
key word |
: |
calculation.densityOfScatteringStates.energyPointWeights |
possible values |
: |
double array with the same length of energyPoints. |
default value |
: |
no default value. |
description |
: |
the weights used in the energy space integration. |
The parameter is used when and only when the |
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isIntegrated is true and the energyPoints is given |
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explicitly. |
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an example |
: |
calculation.densityOfScatteringStates.energyPoints … |
= ones(1,101)/3 |
calculation.densityOfScatteringStates.whatProjected¶
key word |
: |
calculation.densityOfScatteringStates.whatProjected |
possible values |
: |
None, Atom, Orbital, Ell |
default value |
: |
None |
description |
: |
If Atom or Orbital, the DOS is projected on the |
given orbitals or atoms. If Ell, the DOS is projected |
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on orbitals with the given angular momentum. If None, |
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not projected. |
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an example |
: |
calculation.densityOfScatteringStates.whatProjected … |
= Orbital |
calculation.densityOfScatteringStates.indexProjected¶
key word |
: |
calculation.densityOfScatteringStates.indexProjected |
possible values |
: |
cell array of n\(\times\)1 integer array |
default value |
: |
all ells, orbitals, or atoms |
description |
: |
Each cell, which contains a n\(\times\)1 integer array to |
represent a set of atoms or orbitals, or ell values of |
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angular momentum, defines a projector. Density of the |
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scattering states projected on each set of those atoms |
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or orbitals will be calculated respectively. |
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This parameter is not used when whatProjected is |
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None. |
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Please note that the order of the atoms and orbitals |
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have been listed in the output file Atoms.txt, which |
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may help to identify the orbital or atom index. |
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an example |
: |
calculation.densityOfScatteringStates.indexProjected = … |
{[1 4 7], [2 5 8], [3 6 9]} |
calculation.densityOfScatteringStates.whatLocalized¶
key word |
: |
calculation.densityOfScatteringStates.whatLocalized |
possible values |
: |
None, Region, Point |
default value |
: |
None |
description |
: |
If Region, the local DOS will be integrated over a |
given real space region. If Point, the local |
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DOS will be expressed as a function of r. If None, no |
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local analysis is performed. |
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an example |
: |
calculation.densityOfScatteringStates.whatLocalized = Region |
calculation.densityOfScatteringStates.regionPosition¶
key word |
: |
calculation.densityOfScatteringStates.regionPosition |
possible values |
: |
a 3\(\times\)1 double array |
default value |
: |
no default value |
description |
: |
When whatLocalized is Region, this parameter and |
regionVectors define a real space region over which |
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local doss is integrated. When whatLocalized is |
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Point and realSpacePoints is not given, this |
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parameter, regionVectors and regionGridNumber |
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will define the parameter realSpacePoints. When |
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whatLocalized is None, this parameter is not used. |
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an example |
: |
calculation.densityOfScatteringStates.regionPosition = [1,1,1] |
calculation.densityOfScatteringStates.regionVectors¶
key word |
: |
calculation.densityOfScatteringStates.regionVectors |
possible values |
: |
a 3\(\times\)3 double array |
default value |
: |
no default value |
description |
: |
When whatLocalized is Region, this parameter and |
regionPosition define a real space region over which |
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local DOSS is integrated, where the columns of |
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regionVectors are the three basis vectors of the region. |
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When whatLocalized is Point and realSpacePoints |
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is not given, this parameter, regionPosition, and |
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regionGridNumber will define the parameter |
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realSpacePoints. When whatLocalized is None, this |
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parameter is not used. |
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an example |
: |
calculation.densityOfScatteringStates.regionVectors … |
= eye(3)*0.3 |
calculation.densityOfScatteringStates.regionGridNumber¶
key word |
: |
calculation.densityOfScatteringStates.regionGridNumber |
possible values |
: |
3\(\times\)1 integer vector |
default value |
: |
no default value |
description |
: |
the small grid number in each direction. It is used |
to divide the region defined by regionPosition and |
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regionVectors to a number of small grids for |
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integration over the region. When whatLocalized is |
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Point and realSpacePoints is not given, this |
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parameter, regionPosition, and regionVectors define |
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the parameter realSpacePoints. |
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an example |
: |
calculation.densityOfScatteringStates.regionGridNumber … |
= [4 4 4] |
calculation.densityOfScatteringStates.realSpacePoints¶
key word |
: |
calculation.densityOfScatteringStates.realSpacePoints |
possible values |
: |
3\(\times\)n double array with n an integer |
default value |
: |
determined by regionPosition, regionVectors, and |
regionGridNumber |
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description |
: |
the real space points at which the local DOSS |
is calculated. When whatLocalized is None or |
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Region, this parameter is not used. |
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an example |
: |
calculation.densityOfScatteringStates.realSpacePoints … |
= [0 0 0] |
calculation.densityOfScatteringStates.plot¶
key word |
: |
calculation.densityOfScatteringStates.plot |
possible values |
: |
true or false |
default value |
: |
false |
description |
: |
If true, a plot will be given after the calculation. |
an example |
: |
calculation.densityOfScatteringStates.plot = true |