When publishing results obtained with DFT-VASP WaNo, please consider citing it.

Electrolyte-Screening

We use the SimStack framework features to screen the best electrolyte candidates using DFT simulations. Here, we combine four different WaNos: Mult-It, Structure-Generator, DFT-Turbomole, and DB-Generator, to set up an electrolyte system, load the file structure, and choose the methods embedded in the DFT approach using Turbomole code. A .yml file containing the system's HOMO-LUMO gap energy and molecule label is the expected output of this protocol.

Using the drag-and-drop in SimStack's environment, we can build the workflow depicted in Fig 1 in four steps. The Mult-It WaNo accounts for a given system's different configurations. In the second step, we add the Structure-Generator WaNo inside the ForEach loop control to generate the configuration system's .xyz files. In the third step, we insert the DFT-Turbomole WaNo, which will receive the generated files from the previous one. We can take advantage of the parallelization in the HPC remote resources at this step once the ForEach loop control is designed for this end. DB-Generator WaNo generates a lightweight, human-readable database in .yml format for all WaNos of a given workflow.

In this workflow, we will be able to:

1. Set up electrolyte configurations from an initial seed (Mult-It).
2. Load a molecule seed and attach many other molecules to the seed (Structure-Generator).
3. Run the geometric DFT calculations using the Turbomole code, accounting for the proper corrections (DFT-Turbomole).
4. Arrange all the HOMO-LUMO gap energy values of the system in a `.yml` format (DB-Generator).

Electrolyte-Screening with ForEach loop control

Fig 1 This workflow aims to perform several DFT calculations of electrolyte systems. It comprises Mult-It, Structure-Generator, DFT-Turbomole, and DB-Generator WaNos connected by the ForEach loop control. In step 1, we generate the number of configurations. Steps 2 and 3 define the electrolyte designs and the DFT calculation methods employed in the simulation. The WaNo in the last step extracts the inquired variables of the output file from the previous actions.

1. Python Setup

To get this workflow up and running on your available computational resources, install the below libraries on Python 3.6 or newer.

1. Atomic Simulation Environment (ASE).
2. Python Materials Genomics (Pymatgen).
3. Numpy, os, sys, re, yaml, subprocess.
4. json, csv, shutil, tarfile, numpy 

2. Mult-It Inputs

• Float and Int modes
• Range of the variable.
• Number of points in the present in the range.

3. Mult-It Output

• It should pass all the information to the next WaNo inside the ForEach loop through the Mult-It.* command on the top of the loop, as Fig 1 shows.
• Create a variable named dist in the Advance For loop control using numpy, e.g.;

np.linspace(Mult-It.VarF-begin, Mult-It.VarF-end, Mult-It.N-points)

4. Structure-Generator Inputs

• Directory with the zip file of the molecules.
• Position of the attached molecule about seed one.

5. Structure-Generator Output

• .xyz file should be passed to DFT-Turbomole WaNo.

6. DFT-Turbomole Inputs

• Molecular-structure: The user can load the .xyz file from the previous one. WaNo.
• Basis-set: Basis set types.
• Starting-orbitals: charge of the system

7. DFT-Turbomole Output

• ridft.out file
• eiger.out file
• energy file
• job.last file
• control (initial input file of Turbomole code)

8. DB-Generator Inputs

• Search_in_File: The job.last file is imported using ForEach/*/DFT-Turbomole/outputs/job.last command.
• Delete_Files: check the box option.
• Search-Parameters: Set the variables Structure-label and HOMO-LUMO gap.

9. DB-Generator Output

• DB-Name(e.g., db-screening) file in .yml format containing the variables defined in the Search_Parameters field.

Acknowledgements

This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 957189. The project is part of BATTERY 2030+, the large-scale European research initiative for inventing the sustainable batteries of the future.

License & Copyright

Developer: Celso Ricardo C. Rêgo, Multiscale Materials Modelling and Virtual Design, Institute of Nanotechnology, Karlsruhe Institute of Technology https://www.int.kit.edu/wenzel.php

Licensed under the KIT License.