(no subject)

Hi LAMMPS users,

I am extremely new to the simulation environment and I am trying to learn how to simulate firstly the adsorption of CO2 molecules into a metal-organic framework (MOF) and then study the diffusivity property of these gas molecules within the MOF structure. I’ve been trying to read as many posts on the mailing list, but there is still some confusion. I’d like to thank you in advance for taking the time to answer my questions.

In order to first study the adsorption of gas molecules in the system, I assume the “fix gcmc” command will help me do that. But I have a few questions pertaining to this step:

  • Q1. How do I specify using my command that I initially want my gas molecules to be outside the MOF structure and then simulate the number of gas molecules that are absorbed into the structure?

  • Q2. What exactly should my output components be and against what quantities should I be plotting in order to get an adsorption isotherm?

Nextly I want to study the diffusion property of the adsorbed gas molecules through the pores of the MOF structure, for which I assume that “fix nvt” used in combination with the above command will help me do so, am I right in this direction? If yes, I do have some questions concerning the same:

  • Q3. Should I run these simulations separately or can I write them together in one single input script?

  • Q4. In case I can write them together, then how do I use the results that I get from “fix gcmc” to initiate my “fix nvt” command?

  • Q5. What should my output components be and against what quantities should I plot to be able to analyze the diffusivity property?

  • Q6. Firstly I want to study a simple rigid MOF structure, what commands should I keep in my input script to be able to do so? In case I want to study how the flexibility of MOF will change the results, then which commands should I change in order to be able to achieve that parameter?

I’ve attached my input script and the files for MOF and CO2. Please let me know what changes should I make in the input script.

Thank you in advance.

With Regards

co2.dat (372 Bytes)

mof_m_l6_l6_l6.dat (33.2 KB)

input_GCMC.txt (1.47 KB)