16
General Questions and Answers / Re: how to calculate orbital isosurfaces in two probe system
« on: June 9, 2014, 13:53 »
Dr. Blom,
Kindly help to answer my question
Kindly help to answer my question
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17
General Questions and Answers / Re: how to calculate orbital isosurfaces in two probe system
« on: June 9, 2014, 11:54 »
Dear Zh,
For eg. in Comp. Mat. Sci. 27, 151 (2003) K. Stokbro, J. Taylor, M. Brandbyge, J.-L. Mozos, and P. Ordejón. Comp. Mat. Sci., 27, 151, 2003, eigen states of MPSH (fig 3 (c)) and Isosurface of the induced density & contour plot of potential drop at 1 V (fig. 4 (b)) both are calculated. It seems that both the figures are same just having the difference of applied bias. so why they use different name like eigen state and Isosurface?
Kindly reply!
Thanks in advance..
For eg. in Comp. Mat. Sci. 27, 151 (2003) K. Stokbro, J. Taylor, M. Brandbyge, J.-L. Mozos, and P. Ordejón. Comp. Mat. Sci., 27, 151, 2003, eigen states of MPSH (fig 3 (c)) and Isosurface of the induced density & contour plot of potential drop at 1 V (fig. 4 (b)) both are calculated. It seems that both the figures are same just having the difference of applied bias. so why they use different name like eigen state and Isosurface?
Kindly reply!
Thanks in advance..
18
General Questions and Answers / Re: Are LDA and SZP appropriate for two probe calculations??
« on: June 6, 2014, 07:29 »
Please anyone help me to answer my questions ...
19
General Questions and Answers / Are LDA and SZP appropriate for two probe calculations??
« on: June 4, 2014, 10:48 »
Hi ATK-VNL team,
I HAVE 2 QUESTIONS:
(1)In two probe calculations, we generally use localized basis sets such as Single, or double, plus polarization. But according to Stange et al. J. Chem. Phys. 128, 114714 (2008), the convergence of transport properties using localized could be problematic. I want to know the reliability of our calculated results???
(2)Also we use LDA to calculate HOMO-LUMO gap in two probe calculations (for eg. Wang et al. Phys. Lett. A 374, 4876 (2010)). But according to T. Rangel el al. Phys. Rev. B 84, 045426, this approximation strongly underestimate the HOMO-LUMO gap. So again the use of LDA is reliable for our calculation?
Thanks!!!
I HAVE 2 QUESTIONS:
(1)In two probe calculations, we generally use localized basis sets such as Single, or double, plus polarization. But according to Stange et al. J. Chem. Phys. 128, 114714 (2008), the convergence of transport properties using localized could be problematic. I want to know the reliability of our calculated results???
(2)Also we use LDA to calculate HOMO-LUMO gap in two probe calculations (for eg. Wang et al. Phys. Lett. A 374, 4876 (2010)). But according to T. Rangel el al. Phys. Rev. B 84, 045426, this approximation strongly underestimate the HOMO-LUMO gap. So again the use of LDA is reliable for our calculation?
Thanks!!!
20
General Questions and Answers / how to calculate orbital isosurfaces in two probe system
« on: May 6, 2014, 10:08 »
hello quantumwise team,
I want to know how we can do orbital isosurface study of two probe system using ATK-VNL.
Kindly help!
I want to know how we can do orbital isosurface study of two probe system using ATK-VNL.
Kindly help!
21
General Questions and Answers / Re: whether the shape of electrodes effects transport properties of two probe system
« on: April 24, 2014, 09:33 »
Thanks Stokbro & Martinez 
When I go through the link http://dx.doi.org/10.1063/1.1993558 It asks me for login password. I don't have the login password. May you please give me the login password of the link.
Further, Is there any paper in the literature which can help me to understand how the shape of electrodes effects the transport properties of molecular devices.
EDIT: fixed the link
When I go through the link http://dx.doi.org/10.1063/1.1993558 It asks me for login password. I don't have the login password. May you please give me the login password of the link.
Further, Is there any paper in the literature which can help me to understand how the shape of electrodes effects the transport properties of molecular devices.
EDIT: fixed the link
22
General Questions and Answers / whether the shape of electrodes effects transport properties of two probe system
« on: April 21, 2014, 08:16 »
Hello all,
In the ATK tutorial of molecular devices dithiol benzene (DTB) molecule contact with two gold (111) surfaces. Also in other articles like
Z.Y. Li, D. S. Kosov, J. Phys. Chem B 110 (2006) 19116-19120, thiol group attached gold (111) surface.
I want to know whether the shape of electrodes influences the transport behavior of the devices. If yes, then why (111) surfaces is always preferable than other electrode shapes?
Kindly help!!
Thanks & Regards,
Sweta
In the ATK tutorial of molecular devices dithiol benzene (DTB) molecule contact with two gold (111) surfaces. Also in other articles like
Z.Y. Li, D. S. Kosov, J. Phys. Chem B 110 (2006) 19116-19120, thiol group attached gold (111) surface.
I want to know whether the shape of electrodes influences the transport behavior of the devices. If yes, then why (111) surfaces is always preferable than other electrode shapes?
Kindly help!!
Thanks & Regards,
Sweta
23
General Questions and Answers / doubt in relaxing the geometry
« on: February 6, 2014, 12:12 »
Hello quantumwise team,
In two probe system, when i tried to make Au electrode supercell from fcc structure, i got minima at 2.88 A. When i use the electrode with 2.88 inter atomic distance, at the end of relaxation, i get Au-Au distance between 2.68 to 2.80. Au-Au distance is not same for atoms. Is it possible or i m doing some mistakes in taking parameters to make the geometry??? How we can check feasibility of my system???
Kindly help!!!
In two probe system, when i tried to make Au electrode supercell from fcc structure, i got minima at 2.88 A. When i use the electrode with 2.88 inter atomic distance, at the end of relaxation, i get Au-Au distance between 2.68 to 2.80. Au-Au distance is not same for atoms. Is it possible or i m doing some mistakes in taking parameters to make the geometry??? How we can check feasibility of my system???
Kindly help!!!
24
General Questions and Answers / effect of temperature in two probe system
« on: September 11, 2013, 07:33 »
Hi everyone,
In two probe system, can we measure the effect of temperature (of device) on current through ATK. If yes, then how?
Thanks!!
In two probe system, can we measure the effect of temperature (of device) on current through ATK. If yes, then how?
Thanks!!
25
General Questions and Answers / force required to break S-Cu bond
« on: June 21, 2013, 08:50 »
Hi,
As we know the value of force required to break S-Au bond is about 1.5nN in molecular junctions. Likewise what is the value of force required to break S-Cu bond?
As we know the value of force required to break S-Au bond is about 1.5nN in molecular junctions. Likewise what is the value of force required to break S-Cu bond?
26
General Questions and Answers / how we can calculate streching distance dependence using ATK
« on: May 30, 2013, 10:24 »
Dear all,
I have gone through the paper entitled "conductance of streching oligothiophene single-molecule junctions: A first-principles study", J. Physical Chem C, 115, 25105 (2011).
During streching, I have also calculated the distance between Au-S bond on sandwitching biphenyl dithiol molecule between two Au(111)-(3*3) electrodes. Then reoptimize the structure. But after aptization the breaking distance between Au-S bond that I have calculated is much smaller (~2) than reported value (2.36). Why this difference occurs? How i can calculate streching effect correctly?
I have gone through the paper entitled "conductance of streching oligothiophene single-molecule junctions: A first-principles study", J. Physical Chem C, 115, 25105 (2011).
During streching, I have also calculated the distance between Au-S bond on sandwitching biphenyl dithiol molecule between two Au(111)-(3*3) electrodes. Then reoptimize the structure. But after aptization the breaking distance between Au-S bond that I have calculated is much smaller (~2) than reported value (2.36). Why this difference occurs? How i can calculate streching effect correctly?
27
General Questions and Answers / Re: study of asymmetric electrode materials
« on: May 24, 2013, 08:44 »
Thanks Dr. Blom.
How we can insert a molecule between two graphene nanoribbon electrodes to make molecular device geometry using ATK 12.8?
How we can insert a molecule between two graphene nanoribbon electrodes to make molecular device geometry using ATK 12.8?
28
General Questions and Answers / Re: study of asymmetric electrode materials
« on: May 20, 2013, 09:40 »
Hello,
In an article J. Phys. D: Appl. Phys. 46 (2013) 055309 they connect SWCNC directly with electrodes without taking central scattering region and therefore calculate bonding energy easily.
In ATK we take central region, so is this possible to calculate bonding energy? How to calculate this using ATK?
In an article J. Phys. D: Appl. Phys. 46 (2013) 055309 they connect SWCNC directly with electrodes without taking central scattering region and therefore calculate bonding energy easily.
In ATK we take central region, so is this possible to calculate bonding energy? How to calculate this using ATK?
29
General Questions and Answers / Re: study of asymmetric electrode materials
« on: May 10, 2013, 10:05 »
Thanks for your quick response Dr. Blom.
I have made central device region. But when i convert it into device by selecting device from bulk and choosing left and right electrode length, it will change the shapes of electrode materials as that are in case of symmetric electrode materials.
I have made central device region. But when i convert it into device by selecting device from bulk and choosing left and right electrode length, it will change the shapes of electrode materials as that are in case of symmetric electrode materials.
30
General Questions and Answers / study of asymmetric electrode materials
« on: May 10, 2013, 09:25 »
Hello everyone,
I want to study the asymmetric electrodes in two probe system. The problem is that when we change right electrode material by editing script in editor and send to builder, it will convert into bulk rather device mode. How i can convert into proper device mode to study the junction system???
Thanks in advance!
I want to study the asymmetric electrodes in two probe system. The problem is that when we change right electrode material by editing script in editor and send to builder, it will convert into bulk rather device mode. How i can convert into proper device mode to study the junction system???
Thanks in advance!