The application of polymer chain statistics, or configurational statistics, to thenucleic acids has helped to relate the subtle features of chemical architecture to thephysieal and biological properties of these maeromoleeules. Various configuration-dependentproperties (such as mean-square dimensions, average nmr coupling constants,and loop closure probabilities) can be calculated with ready facility in terms of thefixed structural parameters (i. e., bond lengths and valence bond angles) and the seveninternal torsional variables of the nueleotide repeating units. In fact, the configurationalcomputations are the only available means to study the distribution of conformations ofa flexible polynueleotide. The statistical studies are also useful in testing variouseonformational models of the chain backbone. The validity or rejection of a particulartorsional scheme is determined by its ability to account for the various eonfiguration-dependentproperties. The application of polymer chain statistics, or configurational statistics, to thenucleic acids has helped relate to the subtle features of chemical architecture to thephysieal and biological properties of these maeromoleeules. Various configuration-dependentproperties (such as mean-square dimensions, average nmr coupling constants, and loop closure probabilities) can be calculated with ready facility in terms of the structural structural parameters (ie, bond lengths and valence bond angles) and the seven internal torsional variables of the nueleotide repeating units. In fact, the configurationalcomputations are the only available means to study the distribution of conformations of a flexible polynueleotide. The statistical studies are also useful in testing variouseonformational models of the chain backbone. The validity or rejection of a particulartorsional scheme is determined by its ability to account for the various eonfiguration-dependentproperties.