</aside>

Now, you should have already installed RASPA2 on your CCR account if you followed the steps outlined in the installation guidance using EasyBuild. This page will guide you through the steps to run your first RASPA2 simulation!

Download the latest RASPA2 User Manual here. You can find more details about the simulation setup and input files in this user manual.

Let’s start!

First, let’s go to your project space located in /projects/academic/kaihangs, you should have already created a folder with your name there. Go to your named folder:

cd /projects/academic/kaihangs
cd folder_with_your_name

Let’s download the necessary RASPA2 input files in tarball format:

wget "<https://www.dropbox.com/scl/fi/x99aprh9g88u4vm6vbfmo/RASPA2_example.tar.gz?rlkey=ids7wh95fq6qp5qcovufhe8q0&dl=1>"

Let’s rename the downloaded file and unzip it:

mv RASPA2_example.tar.gz\\?rlkey\\=ids7wh95fq6qp5qcovufhe8q0\\&dl\\=1 RASPA2_example.tar.gz
tar -xvf RASPA2_example.tar.gz

The folder “RASPA2_example” contains all input files that are necessary for the simulation. Here, you are going to carry out the grand canonical Monte Carlo (GCMC) simulation to model the adsorption of methane in MFI zeolite.

cd RASPA2_example
ls

Inside the folder, you can see 7 files:
- simulation.input: This is the main simulation input file that specifies essential simulation parameters, such as temperature, pressure, force fields, number of initial and production simulation cycles, and Monte Carlo moves.
- force_field_mixing_rules.def: Force field file that specifies the Lennard-Jones (LJ) interactions parameters between atom types.
- force_field.def: Force field file that specifies specific LJ cross-interaction parameters.
- methane.def: This file defines the structure of methane molecule. Critical properties of methane are also provided in this file for the use of Peng-Robinson equation of state. RASPA2 uses PR EOS to calculate fugacity coefficient, so that it can convert input pressure to fugacity. The fugacity appears in the final equation of MC acceptance criteria.
- MFI_SI.cif: CIF structure file for MFI zeolite. You can visualize this CIF structure in OVITO, Materials Studio Visualizer, or VESTA. See more about the visualization software on the software page.
- pseudo_atoms.def: This file defines the basic properties of each atom type, such as mass, partial charges, etc.
- raspa.job: This is the SLURM job submission file. Learn more about the job configurations on the CCR help page.

<aside> 💡 Learn more about RASPA2 and input files in RASPA2 user manual here.

</aside>

You can open the raspa.job file by vi raspa.job, and see basic job configurations. For this job, you will be running the simulation on our private CPU nodes:

#SBATCH --cluster=faculty
#SBATCH --partition=kaihangs
#SBATCH --qos=kaihangs

Now everything is ready, let’s just submit the job:

sbatch raspa.job

The job may finish quickly, you can check job status by typing:

squeue -M all -u **your_CCR_username**