کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5376050 | 1504312 | 2008 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Accurate ab initio computation of thermochemical data for C3Hx(x=0,â¦,4) species
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
We have computed the atomization energies of nineteen C3Hx molecules and radicals using explicitly-correlated coupled-cluster theory including corrections for core-core and core-valence correlation, scalar and spin-orbit relativistic effects, and anharmonic vibrational zero-point energies. Equilibrium geometries were obtained at the coupled-cluster level [CCSD(T) model] in a correlation-consistent polarized core-valence quadruple-zeta basis set, using a spin-restricted Hartree-Fock reference wave function, and including all electrons in the correlation treatment. Applied to a set of selected CHx and C2Hx systems, our approach yields highly accurate atomization energies with a mean absolute deviation of 1.4Â kJ/mol and a maximum deviation of 4.2Â kJ/mol (for dicarbon) from the Active Thermochemical Tables (ATcT) values. The explicitly-correlated coupled-cluster approach provides energies near the basis-set limit of the CCSD(T) model, which is the coupled-cluster model with single and double excitations (CCSD) augmented with a perturbative correction for triple excitations (T). To obtain even more accurate atomization energies than those presented here, it would be required to include full triple excitations (CCSDT) and corrections for excitations beyond triples, as for instance done in the CCSDT(Q) model, which includes a perturbative correction for quadruple excitations (Q).
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Physics - Volume 346, Issues 1â3, 4 May 2008, Pages 56-68
Journal: Chemical Physics - Volume 346, Issues 1â3, 4 May 2008, Pages 56-68
نویسندگان
Jorge Aguilera-Iparraguirre, A. Daniel Boese, Wim Klopper, Branko Ruscic,