Parameter: nffrq

Definition

Number of fermionic Matsubara frequency points for the two-particle green's function.

The two-particle Green's function $\chi(i\omega_n, i\omega'_n, i\nu_n)$ and vertex function $\mathcal{F}(i\omega_n, i\omega'_n, i\nu_n)$ have three frequency indices where $\omega_n$ and $\omega'_n$ are fermionic frequencies, and $\nu_n$ bosonic frequency:

\[\nu_n = \frac{2n\pi}{\beta}\]

\[\omega_n = \frac{(2n+1)\pi}{\beta}\]

The nbfrq parameter is used to define and generate the bosonic mesh $\nu_n$. The corresponding fermionic mesh $\omega_n$ is defined by the nffrq parameter.

Type

Integer

Default value

32

Component

ALL

Behavior

Determine the size of involved arrays. Only useful when we need to compute the two-particle quantities.

Comment

If the nffrq is too large, the computational time is not bearable. So we suggest to set nffrq $< 128$. The computation of two-particle quantities is extremely time-consuming, though we have tried our best optimizing it.

See nbfrq and nfreq for more details.

Tip

The computation of two-particle quantities has been optimized using the OpenMP multi-thread technology. You can enable this feature in the compiling procedure. See also Compiling environment for more details.