Messages

1

General Questions and Answers / Using VNL, how can i find the hybridization of my strucutre?

« on: May 29, 2018, 17:02 »

Hi all,
As you know that to simulate the surface we use slab model. In order to avoid the states originating from dangling bonds from the bottom surface, we use passivation techniques i.e we passivate these dangling bonds with hydrogen atoms. The procedure to passivate dangling bonds with hydrogen atoms, the procedure using VNL is as follows:
(1) Open Coordinate Tools → Custom Passivator.
(2) Set Hybridization such as Sp,SP2 etc.
(3)Adjust the bond distance among the hydrogen atoms
(4) Press the “Passivate” button.
My question is related to the step no.2 i.e to chose the relevant hybridization for my system. How can I find the exact hybridization for my system using VNL? In other words, as to passivate dangling bonds we need exact information about the hybridization of our system/structure so how can I find that which hybridization is following my structure using VNL? I need your help and suggestion in this regard. Your help would be highly appreciated.
Thank You and looking forward for your nice comments.
Using VNL, how can i find the hybridization of my strucutre?

2

General Questions and Answers / Re: Fixing of fractional or cartesian coordinates in vacume creation for 2D structu

« on: April 27, 2018, 20:06 »

First of all thank you very much for your response and clarification provided.
What I have gained from your explanation is:

Regarding#1: For the vacuum creation, the Cartesian coordinate is better to keep fix.

Regarding#2: While in the case to apply strain (i.e to change the lattice parameters a and b), Fractional Coordinate would be better to keep fix.

Is it right? please comments.

3

General Questions and Answers / Fixing of fractional or cartesian coordinates in vacume creation for 2D structu

« on: April 27, 2018, 10:52 »

As you know that to construct 2D materials (like graphene,Silicene or MoS2 etc) we need to put a vacuum in the z-direction which simply means to enlarge the magnitude of C vector. So my question is that we should need to keep fix the "Fractional" or "Cartesian" coordinate while enlarging the C parameter for the Vacuum creation?

My second question is that: To apply the in-plane biaxial strain we simply change the lattice parameter a and b. So to change a and b, we need to keep fix the "Fractional" or " Cartesian" coordinate in VNL?
Your help and suggestions would be highly appreciated in this regard.

4

General Questions and Answers / High symmetry K-points in the Brillouin zone for the band structure

« on: April 21, 2018, 11:11 »

Hi all,
As you know to calculate a band structure, we need high symmetry k-points (i.e Gamma,M etc) in the Brillouin zone.  So how one can get these high symmetry kpoints for a structure while using VNL.
Your help would be highly appreciated in this regard. I am using VNL only for structure designing purpose, not for calculations.
Thank You