Higher angular momentum functions

The number and type of basis functions strongly influence the quality of the results. The use of a single basis function for each atomic orbital leads to file minimal basis set. In order to improve the results, extended basis sets should be used. These basis sets are named double-f, triple-f, etc. depending on whether each atomic orbital is described by two, three, etc. basis functions. Higher angular momentum functions, called polarization functions, are also necessary to describe the distortion of the electronic distribution due... 

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