Messages

1

General Questions and Answers / Re: electron density

« on: March 16, 2017, 11:26 »

Thank you for your replay. I am calculating the mobility. so, is it possible to extract carrier concentration out of this file? if it can be done please brief on it, if not please suggest the method for calculating the carrier concentration for MoS2.

2

General Questions and Answers / electron density

« on: March 12, 2017, 17:19 »

Hi,
how to calculate the electron density of any 2d material (example: MoS2) at the edge of conduction band?
Thanks in advance....

3

General Questions and Answers / Conductance calculation

« on: February 14, 2017, 07:10 »

hi,
I am trying to calculate conductance from transmission spectrum and I followed the previous tutorials and wrote the input file as below. but I am getting an error like

"File "cond100.py", line 4
    conductance = transmission_spectrum.conductance(electrode_temperatures=[300.,t]*Kelvin)
IndentationError: unexpected indent"

please mention if any modification has to be made or any other method to calculate Conductance.

Thank you                 

4

General Questions and Answers / Re: MoS2 Bandstructure

« on: February 6, 2017, 06:03 »

please observe the zoomed view of the valence band, we should get the maxima at k-symmetry point. but, it is in gamma. how to fix this porblem?

5

General Questions and Answers / Re: MoS2 Bandstructure

« on: February 2, 2017, 16:42 »

Thank you. But if you observe the valence band energy at gamma point has much less value(since it is -ve) compare to k point. I also tried and got the same result but still, it's in indirect band gap only right? is it possible to fix it?

6

General Questions and Answers / MoS2 Bandstructure

« on: February 2, 2017, 06:27 »

hi,
I have obtained bandstructure for single layer MoS2 in DFT calculation using GGA-PBE exchange-correlation and DZP, I am getting indirect band gap, but for single layer structure, it has to be direct bandgap right. I am attaching the input file and the bandstructure please tell me if anything wrong in the process.

Thank you

7

General Questions and Answers / Re: boundary condition in classical potential

« on: December 23, 2016, 18:11 »

Thank you Julian Schneider, is it the same case for device configuration?(calculation of phonon transmission spectrum)

8

General Questions and Answers / boundary condition in classical potential

« on: December 21, 2016, 11:03 »

Hi all,
is it possible to impose boundary condition(periodic or aperiodic) in classical potential? Using DFT we can impose using Poisson solver. if it is possible in classical potential simulation please elaborate it.
Thank you

9

General Questions and Answers / Re: how to obtain the phonon transmission of a desired layer in heterostructure

« on: December 8, 2016, 06:52 »

Dear Petr Khomyakov,
I followed your Instruction, according to the second tutorial (http://docs.quantumwise.com/tutorials/thermoelectrics_cnt_isotope/thermoelectrics_cnt_isotope.html)  we get transmission spectrum of the whole structure but is it possible to get the spectrum of only one layer in heterostructure?

10

General Questions and Answers / Re: how to obtain the phonon transmission of a desired layer in heterostructure

« on: November 27, 2016, 15:51 »

Thank you

11

General Questions and Answers / interlayer distance in classical potential

« on: November 27, 2016, 15:27 »

hi,
I am calculating Interlayer distance between Graphene-MoS2 heterostructure. using DFT we can calculate Interlayer distance by selecting two atoms from the optimized structure then if we select Z-matrix in builder it will give us the distance between atom.

If we are using classical potential, after adjusting the classical potential parameters how to calculate the distance between two layers.
I am attaching the image of the calculated interlayer distance between Gr-MoS2 using DFT, please let me know if any correction has to be made.

Thank you

12

General Questions and Answers / how to obtain the phonon transmission of a desired layer in heterostructure

« on: November 25, 2016, 18:28 »

hi all,
I am working on Graphene-Mos2 heterostructure, is it possible to obtain the phonon transmission spectrum of only Graphene or MoS2 layer in heterostructure? if it is possible, can you brief about how to achieve it?
Thank you

13

General Questions and Answers / total energy for hetro structure

« on: November 21, 2016, 11:14 »

hi,
I am calculating the total energy of graphene-MoS2 heterostructure, total energy it is showing -2975.95839 eV is this value correct? how can we tell its in global minima and is there a way to calculate to find the multiple values of distance vs total energy in a single calculation.
Thank you

14

General Questions and Answers / Re: negative phonon in phonon band structure

« on: October 18, 2016, 16:50 »

Thank you

15

General Questions and Answers / negative phonon in phonon band structure

« on: October 18, 2016, 09:03 »

Hello
 I have calculated phonon band structure of graphene using classical potential but, in phonon band structure ZA band near Gamma position going negative. In reported result, it is positive only. how to solve this?