Gaussian basis functions polyatomic molecules

Qicun Shi research is still underway to combine FSS with Gaussian basis functions to treat larger molecular systems and also to investigate the effect of external fields on the molecular stability and whether or not one can use this approach to selectively break chemical bonds in polyatomic molecules. 

McWeeny [8] and, independently, Boys [9] introduced the Gaussian basis function, which held the key to practical applications to arbitrary polyatomic molecules because of the ease and accuracy with which the associated molecular integrals could be evaluated. The (cartesian) Gaussian basis functions have the form... 

Many qualitative and semiempirical studies followed Mulliken s analysis [6], but it was not until 1960 that the first ab initio calculation on CH2 was published [7] by J. M. Foster and S. F. Boys in the famous April 1960 issue of the Reviews of Modem Physics which contained the papers from a conference on Molecular Quantum Mechanics that was held at the University of Colorado in June of 1959. This is the same Boys who in 1950 introduced the idea of using oscillator functions or as we know them now, gaussian fionctions as basis functions for calculating the electronic structure of polyatomic molecules. 

The integrals over Gaussian-type functions can, therefore, be evaluated efficiently and accurately, a property which makes them by far the most popular choice of basis functions for studies of polyatomic molecules. 

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