Lie Algebraic Study of Infra-Red Active Spectra of Single-Layer Graphene

In this article, using Lie algebraic technique and the expressions of the matrix elements of Majorana and Casimir operators, we obtain an effective Hamiltonian operator, which conveniently describes some stretching infra-red active mode of vibrations of monolayer graphene model of 30 atoms. The model finds the accuracy in results of density functional theory.