ISSN:
0020-7608
Schlagwort(e):
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
We have investigated the conformational dependences of the torsional potential and dipole moment of double-rotor molecules related to acetone, using semiempirical and ab initio calculations and expressing the results in terms of limited Fourier-series expansions. The use of the isodynamic operations of nonrigid molecules to obtain symmetry-adapted quasianalytic forms for the various properties helps compute the representative surfaces with a minimum number of points. Potential surfaces have been calculated for planar ground-state acetone (CNDO/2, STO/3G, and STO/4-31G) and both pyramidal excited-triplet acetone and ground-state dimethylamine (CNDO/2). For groundstate acetone STO/4-31G brings the results obtained with STO/3G closer to those from CNDO/2 and from experiment. The potential surface of excited-triplet acetone appears intermediate between those of ground-state acetone and dimethylamine. For dipole moments the convergence of the harmonic expansions of the vector components is slower than that of the torsional potential whereas that of the vector magnitude is faster.
Zusätzliches Material:
2 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/qua.560220112
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