get_pgen_PC_FastWeightedParticles_t Function

private pure function get_pgen_PC_FastWeightedParticles_t(this, nI, i_sg, I, J) result(p)

Calculates $p(\{I, J\}) \Big |_{D_i}$

This is the probability of drawing two particles from a given determinant $D_i$ regardless of order.

Note that the unordered probability is given by the ordered probability as: $$p(\{I, J\}) \Big |_{D_i} = p((I, J)) \Big |_{D_i} + p((J, I)) \Big |_{D_i} \quad.$$ In addition we have $$p((I, J)) \Big |_{D_i} \neq p((J, I)) \Big |_{D_i}$$ so we have to actually calculate the probability of drawing two given particles in different order.

Type Bound

PC_FastWeightedParticles_t

Arguments

Type	Intent	Optional	Attributes		Name
class(PC_FastWeightedParticles_t),	intent(in)			::	this
integer,	intent(in)			::	nI(nEl)	The determinant in nI-format and the supergroup index
integer,	intent(in)			::	i_sg	The determinant in nI-format and the supergroup index
integer,	intent(in)			::	I	The particles.
integer,	intent(in)			::	J	The particles.

Return Value real(kind=dp)

Contents