Table 1 Modified Morse potential variables and parameters

r (m)

-

Length of C-C bond

r_o (m)

0.1421 × 10⁻⁹

Equilibrium C-C bond distance in graphene

ε

(r − r_o) / r_o

Strain in C-C bond

D_e (Nm)

6.03105 × 10⁻¹⁹

Dissociation energy

β (m⁻¹)

2.625 × 10¹⁰

Constant controlling the ‘width’ of the potential

θ (rad)

-

Current angle of the adjacent bond

θ_o (rad)

2.094

Initial angle of the adjacent bond

k _θ (Nm/rad²)

0.9 × 10⁻¹⁸

Force constant for bond bending

k_sextic (rad⁻⁴)

0.754

Constant in bending term of potential