ISSN: 1813-0410

Keywords : RHF study


Theoretical study for some novelty Triazole derivatives by using Ab Intio calculations(RHF -Model) .

Manal. A. Mohammad; Gehan H. Abdul- Ameer; Lemya S. Mahdi

journal of kerbala university, Volume 11, Issue 4, Pages 168-176

RHF calculations, within Gaussian03 Program, have been carried out after complete optimization of geometry on X and Y disubstituted of (1H1,2,3,-triazole-4-Yl) ethoxy) methy)-1H-1,2,3-triazole) , where X is H , COOH , COCH3 , and 2,3,4,6-Tetra-O-acetyl-β-D-glucopyranosyl. Y is C7H15. It was found that the compound R-sugar the more Stability than other compounds and all of them increasing dipole moment and hardness and decreasing in HOMO and LUMO energies. Geometrical parameters ,total energy ,electron charge ,Ionization energies , and the E0,H0,G0,A0,CP,CV and S0 thermodynamics functions are reported.

QUANTUM MECHANICAL INVESTIGATIONS OF STRUCTUREAL AND THERMAL PROPERTIES OF SOME THIADIAZOL DERIVATIVES

Khidhir Alhameedi; Manal. A. Mohammad

journal of kerbala university, Volume 10, Issue 4, Pages 123-130

This study involved the adoption of the program (Gaussian 03) to use the method of calculating the total (Ab initio of method) according to the Hartree – Fock method (RHF), for the purpose of the expense of dimensional geometry (lengths and bond angles)when the geometry of a balanced, functions thermodynamic, some physical properties, charges for derivatives ring 4-(1,3,4-thiadiazol-2-yl)benzene-1,3-diols.
Have shown calculation results that the compound (R-SiH3) has the highest value of thermodynamic functions (E0,H0,G0,S0,A0) but the compound (R-AlH2) has the highest value of heat capacity (CV,CP ). The results showed that both nitrogen atoms (N9,N8) had the highest negative charge when the compound (R-AlH2) , which makes it a strong legend when Linked to metal and the formation of the complex.
For ( R-AlH2 , R-SiH3 , R-PH2 , R- SH) molecules the calculated some of physical properties ( dipole moment μ in Debye ) , orbital energies (EHOMO , ELUMO in e V ), IP (in e V) , (measurement stability Δ ) , hardness ɳ and Electron Affinity EA ) . Also For these molecules the calculated (ΔHf 0 (in KJ/mole) by using (semi-empirical method AM1 model in MOPAC program). Calculation results have shown that the compound (R-SiH3) the lower value of the heat of formation (the more Stability) as well as has the highest value of ΔE and IP that means it’s the less active between the compounds. This difference in the results come according to the difference of substituted groups.

Electronic Structure, Thermodynamics functions and Physical properties for oxazolo[4,5-b]pyridine Derivatives by Ab Initio calculation (RHF Method)

Khidhir Abdu Hussein Khidhir

journal of kerbala university, Volume 1, Issue 0, Pages 83-93

This study involved the adoption of the program (Gaussian 03) to use the method of calculation the total (Ab initio of method) according to the Hartree - Fock method (RHF), for the purpose of the expense of dimensional geometric (lengths and angles bond) when the geometry of a balanced, functions thermodynamic, some physical properties, charges.
Also, For (R-Cl, R-F, R-CH3, R-NH2, R-NO2) molecules the calculated some physical properties (ΔHf (in kcal/mole), μ (in Debye) ,orbital energies (EHOMO, ELUMO, in eV), IP (in eV) and measurement stability Δ ) by using (semi-empirical method, MINDO/3 model). Have shown calculation results that the compound (R-F) has the lowest value entropy (S0) and heat capacity (Cv, Cp), as well as the lower value of the heat of formation (the more Stability) and the highest value (Δ), as shown by the results of the account that the compound (R-Cl) has the lowest value (EHOMO, Δ) and the highest value for the ionization energy (IP) as well as to the heat of formation , which means that the compound (R-Cl) is less stability and easier ionization compared to other compound. The results showed that both nitrogen atoms (N3, N7) Had the highest value when the compound (R-NH2),which makes it a strong legend when Linked to metal and the formation of the complex.