get_c3_from_system

get_c3_from_system(ket_tuple_list, system_pair, unit=None)[source]
Overloads:

  • ket_tuple_list (Collection[‘KetPairLike’]), system_pair (SystemPair), unit (None) → PintFloat

  • ket_tuple_list (Collection[‘KetPairLike’]), system_pair (SystemPair), unit (str) → float

Parameters:

  • ket_tuple_list (Collection[KetPairLike])

  • system_pair (SystemPair)

  • unit (str | None)

Return type:

float | PintFloat

Calculate the \(C_3\) coefficient for a list of two 2-tuples of single atom ket states.

This function calculates the \(C_3\) coefficient in the desired unit. The input is a list of two 2-tuples of single atom ket states. We use the convention \(\Delta E = \frac{C_3}{r^3}\).

Parameters:

  • ket_tuple_list (Collection[KetPairReal | KetPairComplex | tuple[KetAtom, KetAtom] | Sequence[KetAtom]]) – The input as a list of tuples of two states [(a,b),(c,d)], the \(C_3\) coefficient is calculated for (a,b)->(c,d). If there are not exactly two tuples in the list, a ValueError is raised.

  • system_pair (SystemPairReal | SystemPairComplex) – The pair system that is used for the calculation.

  • unit (str | None) – The unit to which to convert the result. Default None will return a pint quantity.

Returns:

The \(C_3\) coefficient with its unit.

Raises:

ValueError – If a list of not exactly two tuples of single atom states is given.

Return type:

float | PintFloat