VNU Journal of Science Mathematics – Physics, Vol 37, No 2 (2021) 93 99 93 Original Article Theoretical Prediction of the Structural and Electronic Properties of a Single Layer Graphene like Two dimensional Janus GaInSTe Nguyen Van Chuong1,*, Nguyen Ngoc Hieu2, Nguyen Van Hieu3 1Le Quy Don Technical University, 236 Hoang Quoc Viet, Bac Tu Liem, Hanoi, Vietnam 2Institute of Research and Development, Duy Tan University, 3 Quang Trung, Da Nang, Vietnam 3University of Science and Education, 458 To[.]