triqs.operators.util.extractors.extract_U_dict2

triqs.operators.util.extractors.extract_U_dict2()

Dispatched C++ function(s).

[1] (H: Operator,
     ignore_irrelevant: bool = False)
  -> dict[tuple[tuple[int | str | float | [int, len = 3], int | str | float | [int, len = 3]], tuple[int | str | float | [int, len = 3], int | str | float | [int, len = 3]]] -> float | complex]

Extract the density-density interaction \(\frac{1}{2} \sum_{ij} U_{ij} \hat{n}_i \hat{n}_j\) from a many-body operator.

Parameters:

HOperator

The many-body operator.

ignore_irrelevantbool

If true, silently skip irrelevant terms.

Returns:

dict[tuple[tuple[int | str | float | [int, len = 3], int | str | float | [int, len = 3]], tuple[int | str | float | [int, len = 3], int | str | float | [int, len = 3]]] -> float | complex]

Dictionary mapping index pairs \((i, j)\) to coefficients \(U_{ij}\).