QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: GJK on July 25, 2014, 15:31

Title: ZGNR binding energy
Post by: GJK on July 25, 2014, 15:31

Hi,

How to calculate the binding energy in the case of adsorption followed by doping for graphene?

Scrolled through various posts an links I came across only with either adsorption or doping...

Title: Re: ZGNR binding energy
Post by: zh on July 26, 2014, 03:35

For the binding energy between adsorbate on and dopant in graphene:
Total energy of whole system adsorbing an adsorbate and doped by a dopant  -   Total energy of individual system adsorbing an adsorbate  -  Total energy of individual system doped by a dopant  + Total energy of host (i.e., the system without adsorbate and dopant)

Title: Re: ZGNR binding energy
Post by: GJK on August 10, 2014, 10:03

Dear Zh,

First of all thank you.I have a 2 doubts?

Question 1:
Why did you add the total energy of host.It should be subtracted from the composite system know?as

TE(A+B+C)-TE(A+B)-TE(A+C)-TE(A).Which one is correct addition of TE of Host (or) subtraction of TE of Host

Question 2:
The formula which you mentioned for binding energy is valid for  
covalent adsorption and doping
(or)
non-covalent adsorption and doping
(or)
both and doping ???

Your assistance will be appreciated.
 

Title: Re: ZGNR binding energy
Post by: GJK on August 11, 2014, 18:38

Dear Dr.Zh,

Should we add the TE of host (or) subtract the TE of host for a system with host, adsorbent and dopant.

For two systems of host and dopant) you gave the formula to subtract the TE of host as TE(A+B)-TE(B)-TE(A)----A being the host ,B-adsorbent.

Title: Re: ZGNR binding energy
Post by: zh on August 12, 2014, 01:30

Quote from: GJK on August 10, 2014, 10:03

Dear Zh,

First of all thank you.I have a 2 doubts?

Question 1:
Why did you add the total energy of host.It should be subtracted from the composite system know?as

TE(A+B+C)-TE(A+B)-TE(A+C)-TE(A).Which one is correct addition of TE of Host (or) subtraction of TE of Host

Question 2:
The formula which you mentioned for binding energy is valid for  
covalent adsorption and doping
(or)
non-covalent adsorption and doping
(or)
both and doping ???

Your assistance will be appreciated.

1. please think about the conservation of mass.    (A+B+C) +A =  (A+B) +(A+C).

2. It is irrespective of the thing you mentioned.

Title: Re: ZGNR binding energy
Post by: zh on August 12, 2014, 01:47

Quote from: GJK on August 11, 2014, 18:38

Dear Dr.Zh,

Should we add the TE of host (or) subtract the TE of host for a system with host, adsorbent and dopant.

For two systems of host and dopant) you gave the formula to subtract the TE of host as TE(A+B)-TE(B)-TE(A)----A being the host ,B-adsorbent.

The formula in this quote is correct for the calculation of a binding energy of  a dopant in host.

Please understand the correct meaning of the binding energy between adsorbate on and dopant in graphene as posted in my last reply.

If a dopant and a adsorbate coexist in graphene, the binding energy of this complex entity with respect to graphene can be of course estimated by:
Total energy of whole system adsorbing an adsorbate and doped by a dopant  -   Total energy of an isolated adsorbate  -  Total energy of a isolated dopant  - Total energy of host (i.e., the system without adsorbate and dopant)

By the searching of google, you may find the following papers which treat the coexistence of a dopant and adsorbate (or a structural defect) in graphene and could be helpful to you:
Interplay between nitrogen dopants and native point defects in graphene
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.85.165439

Interplay Between Oxidized Monovacancy and Nitrogen Doping in Graphene
http://pubs.acs.org/doi/abs/10.1021/jp504298p?journalCode=jpccck