کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9575302 1504345 2005 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
How should we calculate multi-dimensional potential energy surfaces for an accurate reproduction of partition functions?
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
How should we calculate multi-dimensional potential energy surfaces for an accurate reproduction of partition functions?
چکیده انگلیسی
The potential energy of n-hexane is studied since it constitutes a typical example of a single chain molecule in which various internal rotations are present and a large number of conformations are existing, which cannot be reached by using one-dimensional rotational energy profiles. For an accurate reproduction of the global partition function and all derived thermodynamic properties an adequate description of all possible conformers is necessary. The full three-dimensional potential energy surface of the internal rotations in n-hexane (3D-PES) is calculated at an ab initio level and compared with one-dimensional schemes to reproduce the energy. Due to the higher dimensionality of the relevant potential energy surface, the computational cost is very high. A new approximate scheme based on two-dimensional cuts is proposed that gives good accuracy for the relative conformational energies and kinetic energies at a reasonable computational cost. This scheme is of general use for any long chain molecule.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Physics - Volume 314, Issues 1–3, 18 July 2005, Pages 109-117
نویسندگان
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