Hello I am working on a Physical Chemsitry problem and Am haveing trouble evaluateing a statistical mechanics approach to calulating entropy. I have defined a list Z that contains 12 values for a variable that is used to descirbe a state. The sum:

sum((ln(1-exp(Z[i]/T)),i=1..12)

is supposed to give me the entropy of a system with those 12 possible states (T is Temperature which is to be entered later) When i try to evaluate this (where the value that changes is defined by a list...