کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
203430 460654 2007 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Making equation of state models predictive: Part 1: Quantum chemical computation of molecular properties
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Making equation of state models predictive: Part 1: Quantum chemical computation of molecular properties
چکیده انگلیسی

We perform quantum chemical calculations to determine molecular properties for a set of molecules for later use in equation of state applications. The properties are the dipole moment, the quadrupole moment, the dipole polarizability and the dipole–dipole dispersion coefficient. We study the effect of basis sets and quantum chemical levels on the accuracy of the computed properties. The aim is to find methods that provide a reasonable compromise between accuracy and effort for medium-sized molecules which are typical for equation of state applications. We assess the accuracy of a recent extrapolation method by Cybulski and Haley for the dispersion coefficient in combination with medium-sized basis sets to make it applicable for the molecules we are interested in. We also apply this approach to compute the deviation of the unlike-dispersion interaction coefficient from the geometric mean combination rule which we call dispersion non-ideality. We find that, due to cancellations of errors, the accuracy of the dispersion non-ideality is much higher than that of the calculation of absolute C(6) coefficients.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Fluid Phase Equilibria - Volume 258, Issue 1, 1 September 2007, Pages 16–28
نویسندگان
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