QuAcK/src/Parquet

Overview of the Parquet implementation

Parameters controling the run

The parameters provided by the user are:

• max_it_macro and max_it_micro which set the maximum number of iterations of the macro (one-body) and micro (two-body) self-consistent cycles.
• conv_one_body and conv_two_body which set the convergence threshold of the macro (one-body) and micro (two-body) self-consistent cycles.

The hard-coded parameters are:

• linearize which control whether the quasiparticle equation will be linearized or not. Note that the Newton-Raphson has not been implemented yet.
• TDA which control whether the Tamm-Dancoff approximation is enforced for the BSE problems or not.
• print_phLR and print_ppLR control the print of eigenvalues at each diagonalization.

Files and their routines

• RParquet.f90 is the main file for the restricted Parquet calculation, it is called by RQuack.f90. The main task of this file is to control the self-consistent cycles.
• R_screened_integrals.f90 gathers four subroutines, each one dedicated to the computation of screened integrals in a given channel.
• There are four files dedicated to computed effective interactions in a each channel. For example, R_eh_singlet_Gam.f90 contains three subroutines: one for the OVOV block, one for the VOVO block and one for the full N^4 tensor.

TODO list

Check

• Initial ppRPA@HF eigenvalues checked with Ne DIP in Table 1 of ppBSE paper
• Comment m,s,t channels and perform ehBSE@GW and ppBSE@GW
• Comment d,m channels and perform ehBSE@GT and ppBSE@GT

Required

• Implement diagonal self-energy
• Implement screened integrals in every channels

Improvement

• OpenMP pp Gamma
• OpenMP eh Gamma
• DGEMM pp Gamma
• DGEMM eh Gamma

Long-term

• Implement Newton-Raphson solution of the quasiparticle equation
• Implement Galitskii-Migdal self-energy