Ab initio calculations on the SCF, MP2, CI( SD) and CPF level are presented for disiloxane. The convergence of the results is studied for a series of basis sets of increasing quality. Large basis sets including f functions are necessary to obtain reliable results for the structure and the barrier to
The effects of basis set and electron correlation on the structure and stability of Be4 and Be13
β Scribed by Celeste Mcmichael Rohlfing; J.Stephen Binkley
- Publisher
- Elsevier Science
- Year
- 1987
- Tongue
- English
- Weight
- 475 KB
- Volume
- 134
- Category
- Article
- ISSN
- 0009-2614
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β¦ Synopsis
The preferred structures and dissociation energies of Be4 and Be13 am determined by ab initio methods, including Meller-Plesset perturbation theory, coupied-eluster theory, and multireference CL Both species serve as calibration points for basis set extension and efectron correlation effects. The results are used to interpret binding energies for Iarger Be clusters obtained only at the SCF level with smaller basis sets.
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The optimized geometries for the rotamers of propanal, 2-butanone, isobutyraldehyde, methyl isopropyl ketone, and isobutyric acid obtained using the 3-21G and 6-31G\* basis sets are compared, and systematic changes are noted. The relative 6-31G\* energies using the 3-21G and 6-31G\* geometries are g
A variety of basis sets have been used for geometric and electronic structure studies. Electronic effects were measured using integrated spatial electron populations (ISEP). The two largest basis sets used, 6-31G\* and DZ+P, give significantly different results. Use of two d-orbital sets (6-31G\*[dd
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