Variables

Units

• [-] = no unit
• Integer = any positive integer value
• Energy = RL (number of G-vectors), Ha, mHa (Hartree atomic units), Ry, mRy (Rydberg atomic units), eV, meV (electron volts), K, THz, GHz
• Time = ps, fs, as
• Magnetic field = T
• Electric field = V/mm
• Angle = deg, rad

Formats

• 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: 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

Variable: FFTGvecs (Units: RL) Meaning: Number of G-vectors used in expanding the wavefunctions and in FFT transforms
Tip: It needs careful convergence. Determines the memory needed.

Variable: NGBlkXd (Units: RL) Meaning: Number of G-vectors 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.

Variable: ETStpsX (Units: 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. Has little effect on memory or time.

EnRngeXd/Xs (Units: Energy, Format: Lower limit, Upper limit)
Meaning: Energy range the spectrum is calculated across.
Tip: Energy range

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