RTBSE

Controls options for the real-time Bethe-Salpeter (RTBSE) propagation. Note that running RTBSE requires previous low-scaling GW calculation. Also note that designating this section as RTBSE run but choosing run type ENERGY leads to potential deallocation errors. [Edit on GitHub]

Keywords

Keyword descriptions

SECTION_PARAMETERS: enum = TDDFT

Lone keyword: RTBSE

Usage: &RTBSE TDDFT

Valid values:

  • TDDFT Use TDDFT for density matrix/MO propagation.

  • RTBSE Use RT-BSE for Green’s function propagation

Mentions: ⭐Real-Time Bethe-Salpeter Propagation

Which method is used for the time propagation of electronic structure. By default, use the TDDFT method. Can also choose RT-BSE method, which propagates the lesser Green’s function instead of density matrix/molecular orbitals. [Edit on GitHub]

FT_DAMPING: real = -1.00000000E+000 [fs]

Mentions: ⭐Real-Time Bethe-Salpeter Propagation

Numerical Fourier transform (required for calculation of MOMENTS_FT and POLARIZABILITY) can oscillate when the final values are far away from zero. This keyword controls the exponential damping in the Fourier transform (Fourier transform is used for calculation of MOMENTS_FT and POLARIZABILITY). For negative values (the default), calculates the damping at the run time so that the last point in the time trace is reduced by factor e^(-4). When set manually, determines the time in which the moments trace is reduced by factor of e^(-1). [Edit on GitHub]

FT_START_TIME: real = 0.00000000E+000 [fs]

Mentions: ⭐Real-Time Bethe-Salpeter Propagation

The starting time from which damping is applied and from which on the trace is considered for the Fourier transform (Fourier transform is used for the calculation of MOMENTS_FT and POLARIZABILITY). Useful for real-time pulse - one can specify the center of the pulse as the starting point. [Edit on GitHub]

RTBSE_HAMILTONIAN: enum = G0W0

Usage: RTBSE_HAMILTONIAN G0W0

Valid values:

  • KS Use Kohn-Sham Hamiltonian for Green’s propagation.

  • G0W0 Use G0W0 Hamiltonian for Green’s function propagation

Which Hamiltonian to use as the single-particle Hamiltonian in the Green’s propagator. [Edit on GitHub]