**Theoretical chemistry** . It includes the use of __physics__ to explain or predict chemical phenomena. In recent years, it has been primarily comprised of __quantum chemistry__ , for example, in the application of __quantum mechanics__ to __chemistry__ problems . Theoretical chemistry can be broadly divided into branches such as electronic structure, dynamics, and statistical mechanics.

Summary

[ hide ]

- 1 History
- 2 Branches of theoretical chemistry
- 3 Fields of application
- 4 Source

History

In the process of solving the problems of predicting __chemical__ reactivity , all of the above processes can be used in different depths. Other “varied” areas in theoretical chemistry include the mathematical characterization of “raw” chemistry in various stages (for example in the study of __chemical kinetics__ and the study of the application of the most recent mathematical developments to the basic areas of study for example, the possible application of topology principles to the study of electronic structure.

The last area developed in theoretical chemistry is normally called __mathematical chemistry__ . Part of this discipline can be classified as __Computational Chemistry__ , although computed chemistry usually indicates the application of theoretical chemistry in a specific configuration, usually with some approximate model. Some theoretical chemists apply __Statistical Mechanics__ to create a bridge between the microscopic phenomena of the quantum world and the gross properties of macroscopic systems. Theoretical approaches to chemical problems start in the old days, but until the formulation of the __Schrödinger equation__ by the Austrian physicist __Erwin Schrödinger__The techniques available were both rough and speculative. Currently, much more sophisticated theoretical approaches, based on __Quantum Field Theory__ and Nonequilibrium Green Function Theory, are in vogue.

Branches of theoretical chemistry

__Quantum chemistry__: the application of quantum mechanics to__chemistry____Computational Chemistry__: The Application of Source Code to Chemistry__Molecular modeling__: methods to model molecular structures without necessarily resorting to quantum mechanics. For example: Molecular Binding, Protein-Protein Binding, Drug Design, Combinatorial Chemistry.__Molecular dynamics__: the application of classical Mechanics to simulate the movement of the Center of a formation of atoms and molecules.__Molecular mechanics__: is the modeling of intra- and inter-molecular Potential Energy Surface interactions by means of a sum of interaction Forces.__Mathematical chemistry__: the discussion and prediction of molecular structure using mathematical methods without necessarily resorting to quantum mechanics.__Theoretical chemical kinetics__: the theoretical study of the dynamic systems associated with reactive chemists and their corresponding differential equations.

Fields of application

Historically, the largest field of application of theoretical chemistry has been in the following fields of research:

- [Atomic Physics]]: The discipline that deals with electrons and the atomic nucleus.
__Molecular Physics__: The discipline focused on the__electrons__surrounding the molecular nucleus, and the movement of the nucleus itself. This term usually refers to the study of molecules formed of few atoms in the gas phase. Some consider that molecular physics also includes the study of the general properties of chemists at the molecular level.__Physicochemical__and__Physical Chemistry__: The chemistry investigated by methods as laser techniques,__Microscope__of__tunnel effect__, etc. The formal distinction between the two fields is that physical chemistry is a branch of chemistry, while physical chemistry is a branch of physics. In practice, this difference is very vague.__Many-body theory__: The discipline that studies the effects that appear in systems with a large number of constituents. It is based on quantum__physics,__especially on the formalism of the second quantization and quantum electrodynamics.

Therefore, the discipline of theoretical chemistry is often seen as a branch of the aforementioned fields of research. However, recently, with the appearance of __Density Functional Theory__ and other methods such as __Molecular Mechanics__ , the area of application has been extended to chemical systems that belong to other fields of chemistry and physics such as __Biochemistry__ , Condensed matter physics, __Nanotechnology__ or __Molecular Biology__ .