Rotamer, and conformer

A. Serrallach, R. Meyer, and H. H. Giinthard, Methanol and deuterated species Infrared data, valence force field, rotamers, and conformation. J. Mol. Spectrosc. 52, 94 129 (1974). 

To explore the relevance of symmetry allowed conformations to chemically real structures it is necessary to locate steric-energy minima in a potential energy surface that spans all possible conformations. A variety of computational techniques [210] are available, commonly combined with experimental results retrieved from structural databases [211]. Such procedures have revealed the occurrence of countless different rotamers and conformers, arising from pseudorotation and conformational inversion under special environmental conditions. In addition, situations of disorder in the crystalline state are symptomatic in many cases, of the stabilization of variable intermediate forms. 

This general scheme has been used to calculate rotamer and conformer solvation energies for a variety of cyclic and acyclic molecules [4, 6,7, 8], and has recently been extended to include the calculation of the solvent dependence of reaction rates from a knowledge of the transition state geometry [9]. 

---