لقد استخدمنا طرقاً عددية لحل معادلات Sham-Kohn من أجل نظرية الكثافة التابعيـة مـن خـلال
تقريب الكثافة المحلية، و قمنا بذلك باستخدام كمونات زائفة مختلفة للحصول على بنيـة بعـض المـواد
و خواصها (السيليسيوم Si ،النحاس Cu ، و النيكل Ni) .
لقد استخدمنا عدداً من الكمونات الزائفة للوصول إلى أكثر النتائج دقة، كما قمنا بـإحراء حـسابات
متعددة عن طريق اختيار نماذج مختلفة من النقاط-K ، و طرائق عددية مختلفة من أجل تحقيـق الغايـة
نفسها.
إن نتائج الحسابات التي تم التوصل إليها متوافقة توافقاً كبيراً مع النتائج التجريبية. إن هـذا يمكننـا
من استخدام هذه الطريقة في حسابات مستقبلية لدراسة خواص مواد متعددة.
We have used numerical methods to solve the Kohn-Sham equations of the
Density Functional Theory DFT, within local density approximation LDA
employing different pseudopotentials in order to obtain equilibrium structure
and properties of some materials (namely Si, Cu, and Ni). We used in these
calculations a number of pseudopotentials in order to obtain the most accurate
results, and we varied the computational procedure by choosing different Kpoint
sampling and different numerical methods for the same purpose.
The results we have obtained from these ab initio calculations are in good
agreement with experimental results, which allows us to use the same
techniques for further study of some properties of materials.
References used
Pichett, W. Z. (1989). Comput. Phys. Rep. 9.115
Kohn, W., and Sham. L. J. (1965). Phys.Rev. 140, A 1133
Hohenberg, P. and Kohn. W. (1964). Phys. Rev. 136, 864 B
Theoretical calculations using density functional theory (DFT) both on semi
empirical and Ab initio levels have been carried out for pyrromethene laser
dye and related compounds (PM-chromophore, PM-4m, PM 546, PM650 PM
567 and PM597). We carried o
In this paper, the chemical structure of pectin has been
modified by reacting of carboxyl group in pectin with tetrabutyl
ammonium hydroxide [TBA-OH], (acid-base) reaction, to change
hydrophilic properties by adding hydrophobic alkyl chains to the
In this paper, the chemical structure of chitosan has been
modified by trans esterification reaction with methyl esters both of
octanoic and dodecanoic acid, using potassium carbonate as a based
catalyst, the degree of substitution has been determ
This study was conducted during the 2011-2012 and 2012-2013 seasons in
Abu-Jarash orchards area in Damascus to identify the effect of improved
organic materials as sludge, manure and compost in improving some soil
physical characteristics and whea
Using the Mont Carlo code (MCNP4C2), doses were calculated for organs of
interest such as intestine, urinary bladder, rectum, vagina uterus, pancreas,
spleen, liver, spinal cord and kidneys while patient was undergoing cervix
brachytherapy by LDR