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Enthalpy difference between conformations of normal alkanes: Effects of basis set and chain length on intramolecular basis set superposition errorстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 6 декабря 2018 г.
- Автор: Balabin R.M.
- Журнал: Molecular Physics
- Том: 109
- Номер: 6
- Год издания: 2011
- Издательство: Taylor & Francis
- Местоположение издательства: United Kingdom
- Первая страница: 943
- Последняя страница: 953
- DOI: 10.1080/00268976.2011.558858
- Аннотация: The quantum chemistry of conformation equilibrium is a field where great accuracy (better than 100 cal mol-1) is needed because the energy difference between molecular conformers rarely exceeds 1000-3000 cal mol-1. The conformation equilibrium of straight-chain (normal) alkanes is of particular interest and importance for modern chemistry. In this paper, an extra error source for high-quality ab initio (first principles) and DFT calculations of the conformation equilibrium of normal alkanes, namely the intramolecular basis set superposition error (BSSE), is discussed. In contrast to out-of-plane vibrations in benzene molecules, diffuse functions on carbon and hydrogen atoms were found to greatly reduce the relative BSSE of n-alkanes. The corrections due to the intramolecular BSSE were found to be almost identical for the MP2, MP4, and CCSD(T) levels of theory. Their cancelation is expected when CCSD(T)/CBS (CBS, complete basis set) energies are evaluated by addition schemes. For larger normal alkanes (N>12), the magnitude of the BSSE correction was found to be up to three times larger than the relative stability of the conformer; in this case, the basis set superposition error led to a two orders of magnitude difference in conformer abundance. No error cancelation due to the basis set superposition was found. A comparison with amino acid, peptide, and protein data was provided.
- Добавил в систему: Балабин Роман Михайлович