dyn_S2_expval_exc Function

public pure function dyn_S2_expval_exc(nI, exc) result(res)

Evaluates $< D_i | S^2 | D_j >$

$D_j$ is connected to $D_i$ via the excitation exc.

Note that the sign in front of the off-diagonal elements is always +1 if we assume the NECI order of spin orbitals.

Arguments

Type	Intent	Optional	Attributes		Name
integer,	intent(in)			::	nI(:)	The bra Slater determinant in nI format.
class(Excitation_t),	intent(in)			::	exc	An excitation.

Return Value real(kind=dp)

Contents