title: Conventional strain energies of azetidine and phosphetane: can density functional theory yield reliable results?
abstract: The conventional strain energies for azetidine and phosphetane are determined within the isodesmic, homodesmotic, and hyperhomodesmotic models. Optimum equilibrium geometries, harmonic vibrational frequencies, and corresponding electronic energies and zero-point vibrational energies are computed for all pertinent molecular systems using self-consistent field theory, second-order perturbation theory, and density functional theory and using the correlation consistent basis sets cc-pVDZ, cc-pVTZ, and cc-pVQZ. Single point fourth-order perturbation theory, CCSD, and CCSD(T) calculations using the cc-pVTZ and the cc-pVQZ basis sets are computed using the MP2/cc-pVTZ and MP2/cc-pVQZ optimized geometries, respectively, to ascertain the contribution of higher order correlation effects and to determine if the quadruple-zeta valence basis set is needed when higher order correlation is included. In the density functional theory study, eight different functionals are used including B3LYP, wB97XD, and M06-2X to determine if any functional can yield results similar to those obtained at the CCSD(T) level.
authors.affiliation: Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217, USA.
authors.forename: Shelley A
authors.initials: SA
authors.lastname: Smith
authors.forename: Karen E
authors.initials: KE
authors.lastname: Hand
authors.forename: Melissa L
authors.initials: ML
authors.lastname: Love
authors.forename: Glake
authors.initials: G
authors.lastname: Hill
authors.forename: David H
authors.initials: DH
authors.lastname: Magers
mesh_terms: D001384:Azetidines / Q000737:chemistry*; D015394:Molecular Structure; D017553:Phosphorus Compounds / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D001384:Azetidines; D017553:Phosphorus Compounds; C082735:azetidine