CONTENTS:- Introduction to Symmetry, Group and Matrix in Chemistry; Molecular Symmetry; Multiple Operations and Symmetry Groups; Matrices; Theory of Molecular Groups; Irreducible Representations, Orthogonality Theorem Character Table and Representation of Groups; Qualitative and Quantitative Aspects of Hybrid Orbitals; SALCS and Molecular Orbitals; Splitting of Levels and Terms in Chemical Environment; Matrices, Eigen Values and Eigen Vectors; Group Theory and Molecular Vibrations; Theory of Molecular Vibrations.