QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: GJK on May 7, 2014, 12:34

Title: Physical parameters -reg
Post by: GJK on May 7, 2014, 12:34

Hi,

1. how to calculate the inter planar spacing between atoms in AGNR and ZGNR.
2.also explain me about width and length calculation in AGNR and ZGNR
3.how to calculate the Fermi energy.

Thanks in advance

Title: Re: Physical parameters -reg
Post by: kstokbro on May 9, 2014, 13:39

1,2 you can optimize without constraining in the c-direction, i.e. the direction where the structure is periodic
3. See the output file, or include a chemical potential analysis, check also http://www.quantumwise.com/publications/tutorials/mini-tutorials/134

Title: Re: Physical parameters -reg
Post by: GJK on May 9, 2014, 13:44

Dear sir,

Kindly provide me the formulas and the method of calculating them.

Title: Re: Physical parameters -reg
Post by: GJK on May 9, 2014, 13:53

Dear sir,

Actually I cant understand.Kindly help me to calculate the parameters

Title: Re: Physical parameters -reg
Post by: zh on May 11, 2014, 10:21

"Actually I cant understand.Kindly help me to calculate the parameters".
The 3rd question has already explained by kstokbro.  The chemical potential printed out in the log file is the Fermi energy. Please refer to the manual for the usage of "ChemicalPotential()":
http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.chemicalpotential.html

For the width and length of AGNR and ZNGR, you can estimate them "very very"  easily by using the C-C bond length (e.g., d_{C-C}=1.24 angstrom) in graphene. Along the zigzag edge, the periodic length is about sqrt(3) x d_{C-C}. Along the armchair edge, the periodic length is about 3 x d_{C-C}.

Title: Re: Physical parameters -reg
Post by: GJK on May 13, 2014, 05:35

Quote from: zh on May 11, 2014, 10:21

"Actually I cant understand.Kindly help me to calculate the parameters".
The 3rd question has already explained by kstokbro.  The chemical potential printed out in the log file is the Fermi energy. Please refer to the manual for the usage of "ChemicalPotential()":
http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.chemicalpotential.html

For the width and length of AGNR and ZNGR, you can estimate them "very very"  easily by using the C-C bond length (e.g., d_{C-C}=1.24 angstrom) in graphene. Along the zigzag edge, the periodic length is about sqrt(3) x d_{C-C}. Along the armchair edge, the periodic length is about 3 x d_{C-C}.

Hi Mr.Zh,

Can you provide me some reference articles related to this width and length calculation of AGNR and ZGNR.

Thanks in advance.

Title: Re: Physical parameters -reg
Post by: zh on May 13, 2014, 07:42

"Can you provide me some reference articles related to this width and length calculation of AGNR and ZGNR."
It is quite obvious to understand it from the hexagonal unit cell of graphene.