In this book we have systematically investigated and represented the structural, electronic, phase transition, thermal properties of the heaviest lanthanide compounds (LuX, X = N, P, As) viz. lutetium nitride (LuN), lutetium phosphide (LuP) and lutetium arsenide (LuAs) using an ab-initio calculations based on the density functional theory (DFT). In the subsequent section crystal structure, symmetry and space group have been discussed which are related...