Hi Scott, I know that alpha is not a temperature expansion coefficient .I guess it is a volume expansion coefficient( tell me if I am right). Actually I want to know that is it necessary to fit Ei, 3rd, 4th, cumulant in the fitting procedure .If yes then please tell me how to get them involve in the fit .when I give parameter like guess 3rd, guess 4th . Artemis dont take them . And about Ei I am completely blank.I dont know how to use itand from where i will get it. One more thing is that I am fitting Cu foil, CuO and Cu2O , so how many number of paths should I take . And Thanks a lot for your suggestions With regards Abhijeet