Semiexperimental and mass-dependent structures by the mixed regression method: Accurate equilibrium structure and failure of the Kraitchman method for ethynylcyclohexane
| Autor: | Alberto Lesarri, Marcos Juanes, Jean Demaison, Heinz Dieter Rudolph, Natalja Vogt, Jairo Fernández |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
010304 chemical physics Reference data (financial markets) Ab initio General Physics and Astronomy Thermodynamics Substitution method 010402 general chemistry 01 natural sciences 0104 chemical sciences Bond length Molecular geometry Ab initio quantum chemistry methods 0103 physical sciences Kinetic isotope effect Molecule Physical and Theoretical Chemistry |
| Zdroj: | The Journal of chemical physics. 148(6) |
| ISSN: | 1089-7690 |
| Popis: | The mixed regression method for determination of molecular structures is reviewed and applied to the investigation of ethynylcyclohexane, using both semiexperimental and mass-dependent methods. This methodology provides an efficient and computationally affordable route to obtain accurate molecular reference data, preventing ill-conditioning in the structural least-squares determinations from experimental rotational constants. New supersonic-jet microwave measurements are reported to obtain inertial data for the axial and equatorial species of ethynylcyclohexane, together with all 13C isotopologues of the equatorial form. The semiexperimental equilibrium (reSE) and mass-dependent (rm(2)) structures of the molecule are compared with high-level ab initio optimizations, showing that both methods deliver compatible structures with accuracies of about 0.002 A for bond lengths and 0.2° for bond angles. We confirm that dependable predicates can be obtained for a large variety of bonds. Finally, we verify that the substitution method completely fails to determine a reliable structure for the title compound. |
| Databáze: | OpenAIRE |
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