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arXiv · 1407.1011

Double-hybrid density-functional theory applied to molecular crystals

Kamal Sharkas·Julien Toulouse·Lorenzo Maschio·Bartolomeo Civalleri
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Abstract

We test the performance of a number of two- and one-parameter double-hybrid approximations, combining semilocal exchange-correlation density functionals with periodic local second-order Møller-Plesset (LMP2) perturbation theory, for calculating lattice energies of a set of molecular crystals: urea, formamide, ammonia, and carbon dioxide. All double-hybrid methods perform better on average than the corresponding Kohn-Sham calculations with the same functionals, but generally not better than standard LMP2. The one-parameter double-hybrid approximations based on the PBEsol density functional gives lattice energies per molecule with an accuracy of about 6 kJ/mol, which is similar to the accuracy of LMP2. This conclusion is further verified on molecular dimers and on the hydrogen cyanide crystal.

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Kamal Sharkas, Julien Toulouse, Lorenzo Maschio, Bartolomeo Civalleri. 2014-07-03. Double-hybrid density-functional theory applied to molecular crystals. https://doi.org/10.1063/1.4890439

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