scholarly journals SIMULASI PERUBAHAN DENSITAS MUATAN ADSORPSI ATOM HIDROGEN-GRAFENA DENGAN TEORI FUNGSI KERAPATAN

2018 ◽  
Vol 3 (2) ◽  
pp. 179-184
Author(s):  
Albert Zicko Johannes
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Atom ◽  
Charge Density ◽  
Density Functional ◽  
Structural Changes ◽  
Density Functional Theory Method ◽  
Hexagonal Structure ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Center Position

Abstrak Peristiwa adsorpsi atom Hidrogen pada Grafena menyebabkan terjadinya perubahan struktur Grafena. Perubahan ini mempengaruhi keadaan densitas muatan Grafena. Pada simulasi ini posisi atom Hidrogen pada permukaan lembaran Grafena divariasikan, yaitu pada posisi tepat di atas atom Karbon (Top), posisi di tengah antara dua atom Karbon (Bridge), dan posisi pusat struktur heksagonal (Hollow). Simulasi dilakukan dengan metode Teori Fungsi Kerapatan dengan model Grafena ukuran 2x2. Hasil yang diperoleh menunjukkan adsorpsi atom Hidrogen memilih posisi Top sebagai yang paling stabil dibandingkan dengan posisi Bridge dan Hollow. Hasil dari posisi Top menunjukkan elektron dari atom Hidrogen digunakan mengikat Grafena dengan energi ikat sebesar -1.7 eV. Perubahan densitas muatan menunjukkan terjadinya perpindahan elektron menuju Grafena disertai transformasi isosurface yang unik untuk setiap posisi atom Hidrogen dengan perubahan terbesar terjadi pada posisi Top.  Kata kunci: Densitas muatan, Grafena, Adsorpsi, Teori Fungsi Kerapatan  Abstract [Title: The Simulation of Charge Density Diffrential for Hydrogen Atom - Graphene Adsorption with Density Functional Theory] Hydrogen atom adsorption on Graphene cause structural changes. This change affect Graphene charge density. In this simulation the position of Hydrogen atom on the surface of Graphene sheet are varied out, which is on the position directly above the Carbon atom (Top), the position on the middle between two Carbon atoms (Bridge), and the center position of the hexagonal structure (Hollow). The simulation is done by the Density Functional Theory method with a 2x2 size Graphene model. The results obtained showed that Hydrogen atom adsorption chose the Top position as the most balanced compared with the position of Bridge and Hollow. The results from the Top position indicate that electrons from Hydrogen atom are used to bind the Graphene with binding energy of -1.7 eV. The charge density differential indicate the occurrence of electron transfer towards Graphene accompanied by a transformation of the isosurface that are unique for each Hydrogen atom positions with the biggest change is shown in the Top position.  Keywords: Charge Density, Graphene, Adsorption, Density Functional Theory

scholarly journals SIMULASI PERUBAHAN DENSITAS MUATAN ADSORPSI ATOM HIDROGEN-GRAFENA DENGAN TEORI FUNGSI KERAPATAN

2018 ◽  
Vol 3 (3) ◽  
pp. 179-184
Author(s):  
Albert Zicko Johannes
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Atom ◽  
Charge Density ◽  
Density Functional ◽  
Structural Changes ◽  
Density Functional Theory Method ◽  
Hexagonal Structure ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Center Position

Abstrak Peristiwa adsorpsi atom Hidrogen pada Grafena menyebabkan terjadinya perubahan struktur Grafena. Perubahan ini mempengaruhi keadaan densitas muatan Grafena. Pada simulasi ini posisi atom Hidrogen pada permukaan lembaran Grafena divariasikan, yaitu pada posisi tepat di atas atom Karbon (Top), posisi di tengah antara dua atom Karbon (Bridge), dan posisi pusat struktur heksagonal (Hollow). Simulasi dilakukan dengan metode Teori Fungsi Kerapatan dengan model Grafena ukuran 2x2. Hasil yang diperoleh menunjukkan adsorpsi atom Hidrogen memilih posisi Top sebagai yang paling stabil dibandingkan dengan posisi Bridge dan Hollow. Hasil dari posisi Top menunjukkan elektron dari atom Hidrogen digunakan mengikat Grafena dengan energi ikat sebesar -1.7 eV. Perubahan densitas muatan menunjukkan terjadinya perpindahan elektron menuju Grafena disertai transformasi isosurface yang unik untuk setiap posisi atom Hidrogen dengan perubahan terbesar terjadi pada posisi Top.  Kata kunci: Densitas muatan, Grafena, Adsorpsi, Teori Fungsi Kerapatan  Abstract [Title: The Simulation of Charge Density Diffrential for Hydrogen Atom - Graphene Adsorption with Density Functional Theory] Hydrogen atom adsorption on Graphene cause structural changes. This change affect Graphene charge density. In this simulation the position of Hydrogen atom on the surface of Graphene sheet are varied out, which is on the position directly above the Carbon atom (Top), the position on the middle between two Carbon atoms (Bridge), and the center position of the hexagonal structure (Hollow). The simulation is done by the Density Functional Theory method with a 2x2 size Graphene model. The results obtained showed that Hydrogen atom adsorption chose the Top position as the most balanced compared with the position of Bridge and Hollow. The results from the Top position indicate that electrons from Hydrogen atom are used to bind the Graphene with binding energy of -1.7 eV. The charge density differential indicate the occurrence of electron transfer towards Graphene accompanied by a transformation of the isosurface that are unique for each Hydrogen atom positions with the biggest change is shown in the Top position.  Keywords: Charge Density, Graphene, Adsorption, Density Functional Theory

DECOMPOSITION OF SiH4 ON THE SA TYPE STEPPED Si(100) SURFACE

2002 ◽  
Vol 09 (03n04) ◽  
pp. 1401-1407 ◽  
Author(s):  
ŞENAY KATIRCIOĞlu ◽  
ŞAKIR ERKOÇ
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Atom ◽  
Density Functional ◽  
Reaction Path ◽  
Density Functional Theory Method ◽  
Dissociative Adsorption ◽  
Theory Method ◽  
Functional Theory ◽  
Initial Stage ◽  
The Density Functional Theory

The density functional theory method is used to explore the mechanism of dissociative adsorption of silane (SiH4) on the SA type stepped Si(100) surface. Two reaction paths are described that produce silyl (SiH3) and hydrogen atom fragments adsorbed on the dimer bonds present on each terrace. It has been found that the initial stage of the dissociation of SiH4 on the SA type stepped Si(100) surface shows similarity to the dissociation of SiH4 on the flat Si(100) surface; SiH3 and hydrogen fragments bond to the Si dimer atoms by following the first reaction path.

Does Osmium Carbide Exist? Ab initio Investigation

2006 ◽  
Vol 987 ◽  
Author(s):  
M. Zemzemi ◽  
M. Hebbache ◽  
D. Zivkovic ◽  
L Stuparevic
Keyword(s):  
Mechanical Properties ◽  
Density Functional Theory ◽  
Transition Metals ◽  
Ab Initio ◽  
Density Functional ◽  
Ambient Pressure ◽  
Hexagonal Structure ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Good Agreement

AbstractTransition metals of the platinum group (Os, Ir, Pt, Ru, Re, Rh) do not form carbides and nitrides at ambient pressure. Osmium carbide seems to have been synthesized at zero pressure by Kempter and Nadler forty six years ago. According to the authors, OsC crystallizes in WC-type structure and has a hardness equal to 2000 kg mm-2. Up to date, no other experimental confirmation is available. We studied the electronic and mechanical properties of this hypothetical carbide using an approach based on the density-functional theory. We found that the work of the above mentioned authors is sound. The calculated lattice parameters are in good agreement with that given by those authors and a rough estimate also showed that the hardness given by them is reasonable. However, we found that the hexagonal structure of osmium carbide is electronically and mechanically unstable.

Computational insights into the photophysical and electroluminescence properties of homoleptic fac-Ir(C^N)3 complexes employing different phenyl-derivative-featuring phenylimidazole-based ligands for promising phosphors in OLEDs

2016 ◽  
Vol 45 (7) ◽  
pp. 3034-3047 ◽  
Author(s):  
Jieqiong Li ◽  
Li Wang ◽  
Kenan Sun ◽  
Jinglai Zhang
Keyword(s):  
Density Functional Theory ◽  
Electronic Structures ◽  
Density Functional ◽  
Photophysical Properties ◽  
Density Functional Theory Method ◽  
Theory Method ◽  
Functional Theory ◽  
Phenyl Derivative ◽  
The Density Functional Theory

The electronic structures and photophysical properties of three homoleptic iridium(iii) complexes IrL3 with C^N ligands are investigated by means of the density functional theory method.

Sign in / Sign up

Export Citation Format

Share Document