نتایج جستجو برای: dft

تعداد نتایج: 19542  

Journal: :Circulation 2006
Stefan H Hohnloser Paul Dorian Robin Roberts Michael Gent Carsten W Israel Eric Fain Jean Champagne Stuart J Connolly

BACKGROUND Many patients with implanted cardioverter defibrillators (ICDs) receive adjunctive antiarrhythmic drug therapy, most commonly amiodarone or sotalol. The effects of these drugs on defibrillation energy requirements have not been previously assessed in a randomized controlled trial. METHODS AND RESULTS The Optimal Pharmacological Therapy in Cardioverter Defibrillator Patients (OPTIC)...

Journal: :journal of physical & theoretical chemistry 2010
m. r zardoost s. a. radati h. davoudi m. r. gholami h. aghaei

a theoretical study of the kinetic and mechanism of 3-aug-cope rearrangement in gas phase was performed usingdet methods at b3lyp levels of theory with 6-3114ig(d,p) bass set at 298.i5k. equilibrium moleculargeometries and harmonic vibrational frequencies of the reactant, transition state did product were calculated. then,rate constant and activation thermodynamics parameters were calculated an...

Journal: :journal of physical & theoretical chemistry 2012
m. anafche f. naderi

the structural stabilities, geometry and electronic properties of c24 and some its heterofullerenederivatives are compared at the b3lyp/6-311-efg**//b3lyp/6-31+g* level of theory. vibrationalfrequency calculations show that all the systems are true minima. the calculated binding energies ofheterofullerenes show c24 as the, most stable fullerenes by 9.03ev/atom. while decreasing bindingenergy in...

Journal: :journal of physical & theoretical chemistry 2015
m. abul kashem liton sabrina helen mukta das dipa islam m. rabiul karim

the acidity constants (pka) of thirty four (34) ;-substituted carboxylic acids in aqueous solution havebeen calculated using conductor-like polarizable continuum (c-pcm) solvation model. the gasphaseenergies at the density functional theory (dft-mpw1pw91) and solvation energies athartree fock (hf) are combined to estimate the pka values which are very close to the experimentalvalues where, and ...

Journal: :iranian journal of science and technology (sciences) 2015
a. ahmadi peyghan

adsorption of nh3 and h2o molecules on pristine and b–doped al12n12 nano–cage was investigated using density functional theory, by means of b3lyp and x3lyp functionals. both nh3 and h2o molecules were found to bind to an al atom of al12n12 via chemisorption, releasing energies ranging from –1.48 to –1.53 and –1.16 to –1.22 ev, respectively. the binding energies of x3lyp functional are somewhat ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه مازندران - دانشکده شیمی 1392

در این تحقیق جذب گازهای سمی سیانوژن کلرید و فسژن بر روی نانولوله خالص و دوپه شده با اتم ژرمانیم سیلیکون کرباید تک دیواره زیگزاگ (8،0) انجام شده است. با استفاده از محاسبات نظریه تابعیت چگالی (dft)، برهم کنش این مولکول ها بر سطح نانولوله از نظر انرژی الکترونی جذب، شکاف انرژی و کمیت های الکترونی مانند پتانسیل شیمیایی، سختی شیمیایی و شاخص الکترون دوستی بررسی شده است. نتایج محاسبات نشان داده است در...

Journal: :journal of physical and theoretical chemistry 0
fatih ucun department of physics, faculty of arts and sciences, süleyman demirel university, 32260 isparta, turkey serkan kaya department of physics, faculty of arts and sciences, süleyman demirel university, 32260 isparta, turkey halil oturak department of physics, faculty of arts and sciences, süleyman demirel university, 32260 isparta, turkey

the spectroscopic properties of the 2,2,6,6-tetramethyl-piperidine-1-oxyl (tempo) radicalderivatives of the fullerene (c60) were theoretically investigated. the ground state optimizedstructures of the radical adducts of the fullerene were calculated by using dft (b3lyp) with 6-31g(d) level. it was concluded that a 6-6 ring junction of c60 moiety generally covalently links to thepiperidine ring ...

Journal: :journal of physical and theoretical chemistry 0
kazem mahanpoor department of chemistry, arak branch, islamic azad university, arak, iran majid saghi department of chemistry, arak branch, islamic azad university, arak, iran mohammad hosein bigtan department of chemistry, arak branch, islamic azad university, arak, iran

enaminones are those structures made up three various functional groups including carbonyl, alkeneand amine groups which arelocated along with each other in a conjugate fashion. these compoundsare of much attention due to special characteristics and numerous applications. in the paper, sixvarious enaminone structures were theoretically optimized and after concluding, were compared withequivalen...

Journal: :physical chemistry and electrochemistry 0
m rezaei-sameti department of physical chemistry, faculty of science, malayer university, malayer, 65174, iran f khaje joushaghani department of physical chemistry, faculty of science, malayer university, malayer, 65174, iran

in this work, the effects of as-doped on the adsorption of oxygen gas on the outer and inner surface ofboron nitride nanotube (bnnts) is investigated. the structural parameters, quantum properties involving:bond length, bond angle, homo-lumo orbital, gapenergy, electron affinity, electronegativity, chemicalpotential, global hardness, global softness and nmr parameters of bnnts are calculated at...

Journal: :journal of nanostructures 0
ali hashemizadeh department of physics, payame noor university, tehran, iran vahid mohammadi siavashi department of physics, payame noor university, tehran, iran

in present work, we have calculated the electronic properties including density of states (dos) and electron density for gan, inn and in wurtzite phase for x=0.5. the study is based on density functional theory (dft) with full potential linearized augmented plane wave method (fp-lapw) by generalized gradient approximation (gga-pbesol) for calculating electronic properties. in this report we con...

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