Topics

1

General Questions and Answers / Li+ on graphene surface

« on: April 25, 2018, 09:05 »

Dear Quantumwise

Recently, I am interested in the Li+/ graphene interaction.
However,  I just found that in Quantumwise,  I can just change the charge number of the total system in the basis of "New Calculator".
To my understanding, If i want to have an ionic atom in the DFT simulation, I need to generate the ionic Pseudopotential of Li+ by myself.
Is there any ways to do that by using Quantumwise?
Thanks

Best
JinYou Lu

2

Scripts, Tutorials and Applications / Export QuantumEspresso input

« on: March 19, 2018, 08:31 »

Dear Sir

I have around 80 cif files, and I am wondering if it is possible to generate the quantumespresso input files efficiently by using script.

which may be similar to
BulkConfiguration=nlread("ZZZSSY01.cif")

Export???(("ZZZSSY01.in",BulkConfiguration)

Thank you so much

3

General Questions and Answers / Kawamura Three-body potential in MD simulation

« on: November 13, 2016, 13:34 »

Hello~

I am trying to implement a three-body potential, as shown the equation below or in the attached file.
V_ijk3(r_ji,r_jk,θ)=-f{cos(2(θ_ijk-θ_o))-1}(k₁k₂)^1/2
k1=1/(exp[g_r(r_ij-r_m)]+1)
k2=1/(exp[g_r(r_jk-r_m)]+1)

https://www.researchgate.net/publication/29773387_Physical_Properties_of_Clay_Minerals_and_Water_By_means_Molecular_Dynamics_Simulations?enrichId=rgreq-dfafdda917aaf583a0706dddf4c0f460-XXX&enrichSource=Y292ZXJQYWdlOzI5NzczMzg3O0FTOjI2MDg1Nzk2NzkzNTQ4OEAxNDM5MjA0Nzk0NDM5&el=1_x_3

Is there internal potential which can be used to describe the equation?
Thanks

4

General Questions and Answers / Use molecular dynamics to calculate the surface tension of argon liquid

« on: October 20, 2016, 11:12 »

Dear Sir

I am wondering if it is possible to obtain surface tension (or local pressure) directly from md_trajectory file?
The local pressure can be obtained by using Eq. (7) in the reference.
http://marge.uochb.cas.cz/~jungwirt/paper74.pdf
The first term can be obtained by local temperature times local density.
However, the second term seems to be more complicated.

The attached file is to get a stable vapor liquid interface of liquid argon at 85K by using NVT Berendsen ensemble.

5

General Questions and Answers / Vibration of CO on Cu (001)

« on: September 27, 2016, 14:37 »

Hi Sir
I try to analysiz some vibration modes of a CO molecule on metallic surface.
I already got its streching mode around 2162 cm-1. by simulating an diatomic configuration.
However, once i put CO near metallic surface consiting of 4 layers.
Then use Dynamical Matrix to simulate the CO on Cu (001),
the simulation will run and then struck in somewhere.
This should be a simple example for most users. But i failed to get the simulation resilts
I attached the file, please help to check it, thanks very much.

6

General Questions and Answers / lattice_const_looping struck ....

« on: September 6, 2016, 21:57 »

Dear Sir
I want to scan the lattice to find minimum total energy of structure.
So i use the file in the tutorial to practice it , but it always struck in the calculating Kinetic matrix.
 Please check the attached files,thanks