The critical point divides the eigenstates into metastable condensate and dense state, and gives the maximum number of atoms with which an attractive BEC can hold, and which is in agreement with the experiment on the whole.

• 临界点将本征态分为亚稳的凝聚态和不稳的稠密态，并给出与实验报道相符的吸引BEC所能包含的最大原子数N。