. . . "\\(\\Xi = \\sum_{N_A, N_B, ...} Z(N_A, N_B, ...) \\cdot \\lambda_A^{N_A} \\cdot \\lambda_B^{N_B} \\cdot ...\\), where \\(Z(N_A, N_B, ...)\\) is the canonical partition function for the given number of particles \\(A, B, ...,\\), and \\(\\lambda_A, \\lambda_B, ...\\) are the absolute activities of particles \\(A, B, ...\\)."^^ . "http://en.wikipedia.org/wiki/Partition_function_(statistical_mechanics)"^^ . . "An \"Grand Canonical Partition Function\" for a grand canonical ensemble, a system that can exchange both heat and particles with the environment, which has a constant temperature and a chemical potential." . . "Grand Canonical Partition Function"@en . "http://www.iso.org/iso/catalogue_detail?csnumber=31894"^^ . "\\(\\Xi\\)"^^ .