Variables

Just playing with variable templates

Var1 Var2 Var3 - no units

Units

• None = no unit
• RL = number of G-vectors
• Energy = Ha, mHa (Hartree atomic units), Ry, mRy (Rydberg atomic units), eV, meV (electron volts), K, THz, GHz
• Length = Bohr atomic units a.u.

Formats

• Integer = integer value
• Real = real value
• Complex = ( real part , imag part )
• String = string
• Range = Lower limit | Upper limit |(in the specified Unit)
• Integer range = Lower limit | Upper limit (integer values)
• Vector = x | y | z | (in Cartesian coordinates, sandwiched by %)

Ranges can also be split on multiple lines.

Initialization

Variable: MaxGvecs (Units: RL/Energy) Meaning: Number of G-vectors in screening
Tip: This determines the size of the dielectric matrix in G-space. Needed for inclusion of local field effects. It should be much smaller than the number of G-vectors needed to expand the wavefunctions. It needs careful convergence.

Optics-basic

Chimod (Units: None, Format: String)
Meaning: Type of kernel in TDDFT Dyson equation.
Tip: Do not set this manually - set using the appropriate -k command line option. Allowed values: IP/Hartree/ALDA/LRC/BSfxc. IP indicates no kernel (independent particle level/RPA without local fields).

NGBlkXd/Xs (Units: RL/Energy, Format: Integer/Real)
Meaning: Number of G-vectors or energy cut off in the screening.
Tip: Determines the size of the dielectric matrix in G-space. Needed for inclusion of local field effects. It should be much smaller than the number of G-vectors needed to expand the wavefunctions. It needs careful convergence.

ETStpsX (Units: None, Format: Integer)
Meaning: Number of energy steps.
Tip: Determines the number of steps in energy the response function/spectrum is computed for in the desired range defined by EnRngeX.

EnRngeXd/Xs (Units: Energy, Format: Range)
Meaning: Energy range the spectrum is calculated across.
Tip: Energy range blah blah

LongDrXd/Xs (Units: Length, Format: Vector)
Meaning: Electric field direction.
Tip: Electric field direction

BndsRnXd/Xs (Units: None, Format: Integer range)
Meaning: Range of bands included in the sum.
Tip: Range of bands incluein blah blah

DrudeWXd/Xs (Units: Energy, Format: Complex)
Meaning: Drude plasmon energy and inverse lifetime.
Tip: Drudes

Chimod= "IP" # [X] IP/Hartree/ALDA/LRC/BSfxc NGsBlkXd= 1 RL # [Xd] Response block size % QpntsRXd

 1 | 14 |                   # [Xd] Transferred momenta

% % BndsRnXd

  1 | 100 |                 # [Xd] Polarization function bands

% % EnRngeXd

 0.00000 | 10.00000 | eV    # [Xd] Energy range

% % DmRngeXd

 0.10000 |  0.10000 | eV    # [Xd] Damping range

% ETStpsXd= 100 # [Xd] Total Energy steps % LongDrXd

1.000000 | 0.000000 | 0.000000 |        # [Xd] [cc] Electric Field

%

===Optics-advanced=== Here anything needing verbosity

FFTGvecs (Units: RL/Energy, Format: Integer/Real)
Meaning: Number of G-vectors or energy cut off for expanding the wavefunctions/FFT transforms
Tip: It needs careful convergence. Determines the memory needed.

Coulomb cutoff

CutRadius (Units: Length, Format: Real)
Meaning: Sphere/cylinder radius.
Tip: TIP

CUTBox (Units: Length, Format: Vector)
Meaning: Box sides.
Tip: BOX

CUTGeo (Units: None, Format: String)
Meaning: Cutoff geometry.
Tip: Allowed values are: box/cylinder/sphere X/Y/Z/XY...

GW

Variable: EXXRLvcs (Units: RL) Meaning: Number of G-vectors used in the sum of the exchange self-energy Sx.
Tip: It needs careful convergence: not particularly time consuming, large values can be used to ensure convergence.

Variable: QPkrange (Units: Integers) Meaning: First and last Indexes of kpoints and bands the slef energy correction is calculated
Tip: If interested in non consecutive kpoints or bands multiple rows can be also considered