Article title: Determining the structure of functionalized graphene for tailored thermomechanical properties using ML techniques.
Authors: Ravil Ashirmametov, Alexandr Alpatov, Farrokh Yousefi, Narges Vafa, Siamac Fazli and Konstantinos Kostas.
Corresponding author: Ravil Ashirmametov, ravil.ashirmametov@nu.edu.kz
Two datasets are uploaded in the /datasets:
File names are Results_for_H.csv for hydrogen case, and Results_for_methyl.csv for methyl case. Datasets are structured as follows:
8528 columns with integer encoding of the layout (1,2,3,4 integer values)
Four columns with extracted thermomechanical properties, in order:
1. Kappa
2. Max Strain
3. Max Stress
4. Young's Modulus
For the 8528 columns representing the layout:
1 (both cases) - carbon atom without functionalization;
2 (hydrogen case) - carbon atom and top functionalization with hydrogen atom;
3 (hydrogen case) - carbon atom and bottom functionalization with hydrogen atom;
3 (methyl case) - carbon atom and top functionalization with methyl group;
4 (methyl case) - carbon atom and bottom functionalization with methyl group.
Two attached LAMMPS scripts are in the /LAMMPS Sample Scripts:
sample_mechanical is a LAMMPS script used for MD simulation of the graphene for extraction of three targeted mechanical properties (Young's Modulus, maximum stress, strain at maximum stress);
sample_thermal is a LAMMPS script used for MD simulation of the graphene for extraction thermal conductivity.
To go from the integer encoding in the datasets to a LAMMPS data file, we use following encoding strategy:
To go from LAMMPS data file to the integer encoding in the datasets we use the following encoding strategy: We consider unit cells consisting of four atoms, as shown in figure with numbers 1,2,3,4. Then, this unit cell is repeated 52 times along x-axis. This is followed by repeating the row 42 times along y-axis. Whenever functional group is encountered we assign value of 2,3 or 4 as described above.
To go back from the integer vector to a data file we firstly map the carbon atoms to unfunctionalized graphene sheet and then attach functional groups, whenever value not equal to one is encountered in the vector.