Mixed basis set calculations for atomic hydrogen on beryllium(0001)

Abstract

The chemisorption of H on small Be clusters was previously investigated using both minimum basis (MB) and double-zeta (DZ) basis sets. Wavefunctions calculated with DZ basis sets give a much better representation of molecular properties and those calculated with MB. However, it is computationally much more difficult to carry out DZ, rather than MB, calculations on large clusters. The chemisorption is reinvestigated using a mixed basis set, consisting of a double-zeta basis set for the H and Be atoms directly involved in the bonding and a minimum basis for all others. This mixed basis set is a very attractive alternative to the use of either all MB or DZ basis sets. The MB atoms provide an environment of the atoms involved in the local bonding to the adsorbate, while the DZ basis allows for a reasonably flexible description of the bonding. The mixed basis calculations are only slightly more difficult than the all MB calculation, however, the results of the mixed basis calculation are found to be very similar to the more difficult all DZ calculations. © 1982.