First-principles investigation of the impact of high pressure on the structural , electronic and elastic properties of the type-VIII barium-doped silicon clathrate Ba 8 Si

Nassim Ahmed MAHAMMEDI 1,2, Marhoun FERHAT 2, 3 1 Laboratoire de physique des matériaux LPM, Amar Télidji University of Laghouat, BP37G, Laghouat 03000, ALGERIA. 2 École Normale Supérieure de Laghouat (ENSL),RN01, Laghouat 03000, ALGERIA. 3 Department of physics, The University of the West Indies, Mona, Kingston 07, JAMAICA. Corresponding author Nassim Ahmed MAHAMMEDI n.mahammedi@lagh-univ.dz Abstract