Type | Intent | Optional | Attributes | Name | ||
---|---|---|---|---|---|---|

real(kind=dp), | intent(in) | :: | mat_ele |
|||

real(kind=dp), | intent(in) | :: | pgen |

```
subroutine fill_frequency_histogram(mat_ele, pgen)
! routine to accumulate the H_ij/pgen ration into the frequency bins
! keep parallelism in mind, especially if we have to adjust the
! bin list and boundary list on the fly.. this has to happen on
! all the processors then or? or can i just do it in the end of a loop
! adapt this function now, to discriminate between single and double
! excitations, and it pParallel is used, which can be determined
! through the excitation matrix and the 2 involved determinants
! (or even the starting determinant) and fill up to 3 frequency
! histograms .. this also means that we have to reset them maybe
! after pSingles or pParallel have been changed since the pgens
! and so the H_ij/pgen ratios change (or? can i modify that somehow
! on the fly?) think about that later and with ali..
! and for the guga stuff, if i finally implement similar pgens like
! pParallel, as it is already done in the nosym_guga case, i have
! to use even more histograms, but that should be fine.
real(dp), intent(in) :: mat_ele, pgen
character(*), parameter :: this_routine = "fill_frequency_histogram"
integer, parameter :: cnt_threshold = 50
real(dp) :: ratio
integer :: ind
! first have to take correct matrix element, dependent if we use
! complex code or not, or no: for now just input the absolute value
! of H_ij, so its always a real then..
! nah.. it puts in 0 mat_eles too.. so just return if 0 mat_ele
ASSERT(pgen > EPS)
! if the matrix element is 0, no excitation will or would be done
! and if the pgen is 0 i also shouldnt be here i guess.. so assert that
if (mat_ele < matele_cutoff) then
! misuse doubles for the counting here
zero_doubles = zero_doubles + 1
return
end if
if (pgen < EPS) return
! then i have to first check if i have to make the histogram bigger...
ratio = mat_ele / pgen
if (ratio < max_frequency_bound) then
! the ratio fits in to the bins now i just have to find the
! correct one
if (.not. enough_doub_hist) then
cnt_doub_hist = cnt_doub_hist + 1
if (cnt_doub_hist > cnt_threshold) enough_doub_hist = .true.
end if
ind = int(ratio / frq_step_size) + 1
! increase counter
frequency_bins(ind) = frequency_bins(ind) + 1
else
above_max_doubles = above_max_doubles + 1
end if
if (ratio > gamma_doub) gamma_doub = ratio
if (ratio < min_doub) min_doub = ratio
end subroutine fill_frequency_histogram
```

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