The present book is written for research and postgraduate students who are interested to get first hand information about various electronic and thermal properties of binary (II-VI, III-V) and ternary (I-III-VI2, II-IV-V2) semiconductors. In this book, simple models based on plasma oscillations theory of solids, have been proposed for the calculation of various bond parameters such as bond length, energy gaps, ionicity and dielectric constant for these groups of semiconductors. Two simple models have been proposed for the calculation of heats of formation. One is based on the spectroscopic model of Phillips and Van Vechten and other is based on the best fit of the data of heat of formation and plasmon energy. Finally, simple relations between plasmon energy and thermal expansion coefficients have been developed. Special care of delocalization of noble metal d-electrons effect has been taken into account in the case of I(Cu, Ag)-VI bond in the I-III-VI2 semiconductors. The calculated values of above parameters are in fair agreement with the experimental values and the values reported by other workers.