The present application of configurational statistics to model the nucleic acids or polynucleotides provides an essential first step in relating the subtle features of chemical architecture to the unique physical and biological properties of these macromolecules. Through a combination of molecular modeling, potential energy calculations, and statistical mechanical analyses it is possible to elucidate details of nucleic acid conformation and to provide a rational understanding of observed experimental phenomena. The primary objectives of the program are to classify and understand the complex array of nucleotide conformers, to comprehend the effects of primary chemical sequences on secondary and tertiary structure, and to elucidate pathway of conformational transitions. The combined computations should enhance our comprehension of both polynucleotide extension and flexibility offering new structural insight into conformation and the irregularities of various forms. The chain statistics studies may also provide a molecular basis for understanding the nature and flexibility of specifically constrained structures such as small closed circles, loops, knots, hairpins, bulges, and cruciforms.