Abstract
Alkaline earth dimers have small bond energies (less than 5 kcal/mol) that provide a difficult challenge for electronic structure calculations. They are especially challenging for Kohn-Sham density functional theory (KS-DFT) using generalized gradient approximations (GGAs) as the exchange-correlation density functional because GGAs often do not provide accurate results for weak interactions. Here we treat alkaline earth dimers from six different rows of the periodic table. We show that the dominant correlating configurations are the same in all six dimers. We also show that multiconfiguration pair-density functional theory (MC-PDFT) using a fully translated GGA as the on-top density functional not only performs much better than KS-DFT with GGAs in predicting equilibrium distances and dissociation energies but also performs better than the more computationally demanding complete active space second-order perturbation theory (CASPT2) with large basis sets and performs even better than CASPT2 with smaller basis sets.
Original language | English (US) |
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Pages (from-to) | 799-805 |
Number of pages | 7 |
Journal | Journal of Physical Chemistry Letters |
Volume | 10 |
Issue number | 4 |
DOIs | |
State | Published - Feb 21 2019 |
Bibliographical note
Funding Information:This work is supported in part by the National Science Foundation under Grant No. CHE-1464536.
Funding Information:
This work is supported in part by the National Science Foundation under Grant No. CHE−1464536.
Publisher Copyright:
© 2019 American Chemical Society.