1. A method of modeling at least one physical property of a mixture of at least two chemical species, the method comprising the computer implemented steps of: a) determining at least one conceptual segment for each of the chemical species, including defining an identity and an equivalent number of each conceptual segment; b) using the determined conceptual segments, computing at least one physical property of the mixture; and c) providing an analysis of the computed physical property, wherein the analysis forms a model of the at least one physical property of the mixture.