Similarity analysis of the conformational potential energy surface of n-pentane

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• 作者：Gyula  ; Tasi ; Balá ; zs  ; Nagy  ; ;   ; ^{n.balazs@chem.u-szeged.hu} ; Gergely  ; Matisz¹ ; Tamá ; s S.  ; Tasi
• 关键词：Quantum chemical methods ; Critical points ; Minimal energy reaction paths ; Similarity ; Cumulative similarity indices ; Conformational similarity graph
• 刊名：Computational and Theoretical Chemistry
• 出版年：2011
• 出版时间：February 2011
• 年：2011
• 卷：963
• 期：2-3
• 页码：378-383
• 全文大小：764 K

文摘

Wave-function-based ab initio (M?ller¨CPlesset perturbation theory and Hartree¨CFock SCF), tight-binding (SEOEM), semiempirical (MNDO, AM1, and PM3) and density functional (B3LYP) quantum chemical methods have been applied to the generation of the full conformational potential energy surface of n-pentane. All the critical points (local minima, first-order saddle points, and local maxima) have been localized in each case. Their numbers, 11, 20, and 9, respectively, are precisely in accordance with the topological theory of periodic functions. There are fourteen unique critical points on the conformational potential energy surface of n-pentane.

Cumulative similarity indices computed for pairs of conformational potential energy surfaces have revealed that of the generated surfaces the SEOEM one is the most similar to that obtained at the M?ller¨CPlesset level of theory. Surprisingly, the highest similarity index has been obtained for the pair of the Hartree¨CFock and B3LYP surfaces.