Computational chemistry is a branch of Theoretical chemistry that uses a digital computation to model systems of chemical interest The increasing power and availability of computers and the simultaneous development of well tested and reliable theoretical methods The one of the computational chemistry as an adjunct to experimental research as increased rapidly Calculation ranging from few seconds to many hours of computer time can serve as a guide to include less favourable reaction or unstable products In addition advantage has taken to select more fruitful procedures through many possible ways in addition to modelling which enables the researcher to examine them on a scale of space or time yet immeasurable by experimental techniques Thus computational chemistry yield information which may not be experimentally available Computational chemistry refers to the application of tools of information technology for storage visualization interpretation retrieval and acquisition of chemical data In this book I had carried out the Quantitative Structure-Activity Relationship QSAR and docking studies of the derivatives of anti-tuberculosis agent PA 824 and had initiated an attempt to develop a successful model by Quantitative Structure-Activity Relationship techniques
