Assessing weak hydrogen binding on Ca+ centers: An accurate many-body study with large basis sets

作者：Purwanto Wirawan^*; Krakauer Henry; Virgus Yudistira; Zhang Shiwei

来源：Journal of Chemical Physics, 2011, 135(16): 164105.

DOI：10.1063/1.3654002

Weak H-2 physisorption energies present a significant challenge to even the best correlated theoretical many-body methods. We use the phaseless auxiliary-field quantum Monte Carlo method to accurately predict the binding energy of Ca+ - 4H(2). Attention has recently focused on this model chemistry to test the reliability of electronic structure methods for H-2 binding on dispersed alkaline earth metal centers. A modified Cholesky decomposition is implemented to realize the Hubbard-Stratonovich transformation efficiently with large Gaussian basis sets. We employ the largest correlation-consistent Gaussian type basis sets available, up to cc-pCV5Z for Ca, to accurately extrapolate to the complete basis limit. The calculated potential energy curve exhibits binding with a double-well structure.

• 出版日期2011-10-28