Setting up Computational Chemistry (Quantum Chemistry) laboratory? Technical stuffs [Part II].

Anant　Babu Marahatta
Ph.D. student in chemistry
Tohoku University, Japan



(Interested fellows are suggested to read the first part [Part 1] of this article archived herewith before proceeding it).

The designation of the molecular model is another mandatory step before performing any sorts of computer calculations. Several model making software (molecule model builder) are available free of charge. Mercury, RasMol, CHIME, SwissPDB Viewer, Avogadro etc. are some of them. How to handle them is the matter of their practice. It is very essential to know that some of the molecular builders do not support the calculating software. Let’s say in this step that we could model the sample system of our interest and get the Cartesian co-ordinates or Z-matrix of it (generated by the molecular builder) which will be our input for exploring the chemistry behind it.

Let’s move to the calculating software, one of the very well-known is GAUSSIAN (currently Gaussian-09 version for the windows G09W is available) owned by the Gaussian Inc., USA. It is very flexible software developed by the quantum chemists of all around the world. It is very trustworthy for the most accurate calculations especially ab initio, MD simulation and some semi-empirical calculations. Thus, for having the copy of this software, the university must be the member of it and get the license. The normal cost for the single computer license (single CPU version) is $1150 and for the multiprocessor /core version is $1725 (excluding shipping charge). The detail information is available here.

Here is the sample video of "Gaussian in action" to analyze the frequency.

http://www.gaussian.com/g_prod/g09.htm Similarly, individual person can get the license but he or she needs to pay some additional amount provided that Gaussian Inc. trusts him or her.

It is recommended that “GaussView” (currently, GaussView5 for windows GVW5 is available) is very useful molecular builder that supports the Gaussian software windows version. One must get the copy of it too from the Gaussian Inc. The new license costs $875 for the single windows computer and $4025 for the unlimited windows computer provided that Gaussian software has already been installed.

So far, we have installed the very essential software and our computer is ready to compute the chemistry of the input (of the interested molecular system) prepared by using molecular builder. Now, it’s time to know how to handle above installed software, prepare and route proper inputs, submit for the calculations, route the outputs, visualize the outputs and analyze them. The real chemistry starts from here and for it one must be perfect on computational/quantum chemistry.