Hi Matt, Concerning the third cumulant, my problem is to use a particular model for it. Some articles (Frenkel and Rehr, PRB 48 (1993) 585; Araujo et al, PRB 74 (2006) 184102) show how to use the Einstein model on Artemis, since these articles show the expressions that should be defined for sigma^2(T) and C3(T) for this model in Artemis (eqs. 11 and 18 of Frenkel and eqs. 2 and 3 of Araujo). In fact, I have already tested them on my analysis, using the eins function for sigma^2 and defining the C3(T) expression given in those articles in Artemis. I'd like to test Debye model too, and my problem is to use Debye model for sigma^2(T) and C3(T). For sigma^2(T) Artemis has the debye function already predefined. I'd like to use/write an expression for C3(T) considering Debye model, but I didn't find anything about such expression on the literature. Kleber