Accurate theoretical determination of the structure of aromatic complexes is complicated: the phenol dimer and phenol...methanol cases.
The structure of the phenol dimer and phenol...methanol complexes was determined by gradient optimization using the Hartree-Fock (HF), MP2, DFT, and RI-DFT-D methods with various basis sets. Theoretical rotational constants were compared with experimental values and the following conclusions were made: (1) HF and DFT methods fail to predict cluster geometries; (2) MP2 with a medium basis set yields reliable cluster geometries but only because of a compensation for errors; (3) when the AO basis set is enlarged, the geometry becomes incorrect, and the theoretical geometry becomes reliable only when the higher correlation energy contributions (CCSD(T)) are included; and (4) the RI-DFT-D procedure covering the dispersion energy provides excellent geometries.
Kolár
Michal
M
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nAm. 2, 166 10 Prague 6, Czech Republic.
Hobza
Pavel
P
D019281:Dimerization; D000432:Methanol / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D019800:Phenol / Q000737:chemistry*
D019800:Phenol; D000432:Methanol