How Drug Is Design?

Trial and error screening method for the designing of drugs are now overcome by Computational Technique. It acts as information storage of information obtained by different method regarding a particular molecule and it's analogue. These methods are,
1) Molecular mechanics gives geometry and strain energy of molecule.
2) Molecular dynamics used to study internal molecular motion and to elucidate the structure.
3) Quantum mechanics used to calculate the properties of isolated molecules.

Computational technique provides a design tools to the chemist to explore all the pathway leading to the target molecule.