What is Computational Chemistry?
Keywords: software, articles, equations, models
Computational chemistryis the part ofchemistrythat uses computer simulation to help solve chemicalproblems. It uses aspects of the theory of chemistry, incorporated into complex computer programs, to calculate the structures and properties of molecules and solids. Examples of its use can be found in method development, in electronic structure theory, reaction dynamics;modelling of local, global and planetary atmospheres, modelling of disordered solids and minerals including thin film growth, modelling of organic and organometallic structure and reactivity, statistical mechanics and the study of colloidal dynamics.
In general, it can take from hours to years to construct computational models. The number of calculations in an individual program can vary hugely.For example in molecular dynamics simulations there are many millions of steps.Some simpler models can be performed on a laptop, more elaborate ones need the mostpowerful computers in the country.
It is of course, vital to validate the model by comparison with experimental data. In some cases the aim of the computational chemistry research is to reproduce a value to compare directly with the experimental measurement. In general the idea is to generate a model, validated by its ability to reproduce key properties, but which is then used to generate further information,for example about t how atoms and molecules in a particular system behave or the mechanisms involved in different physical and chemical processes In general there are no experimental techniques that can give the wealth of detail that such simulations can!
Sometimes computational simulations do show unexpected data - this should be in the accompanying text. For example, when researchers tried to model thin films of zinc oxide (ZnO)it was found that such thin films changed structure from one in which the atomsare tetrahedrally-coordinatedto a graphene-like structure. After it was predicted it, it was subsequently found experimentally.
Computer models generated by research are used industrially.Indeed individual companies will sponsor such research in universities. In the link below a lot of the DL_MESO work for example is sponsored by the firm Unilever.
Professor Neil Allanis a Professor of Physical Chemistry at the Centre for Computational Chemistry in the School of Chemistry, University of Bristol.
Unlike other members of this resource there are no questions to answer here. Indeed, students are invited to look through some specific examples of computational research that can be found on the links.
Links
1.DL_MESO software package examples
the features Examples of the computational chemistry software ‘DL_MESO’ package to demonstrate of both the Lattice Boltzmann Equation (LBE) and Dissipative Particle Dynamics (DPD) codes can be found here.
2.Argon: the particle sandbox app
This is free particle simulation software. Argon is a molecular dynamics simulator, a technique used in chemistry to model the behaviours of atoms and molecules, and even large biological structures. Using Argon, you can watch crystals form at low temperatures, or see particles bounding around at high temperatures. Change the way the particles react to each other, and see the dynamics change in real time. You can even add areas of attraction or repulsion and control them by making noise. This is a University of Bristol project that is on-going and so the app will evolve.
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