Berlin 2024 – scientific programme

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O: Fachverband Oberflächenphysik

O 108: Electronic Structure Theory II

O 108.3: Talk

Friday, March 22, 2024, 11:00–11:15, MA 043

A Multimer Embedding Approach for Molecular Crystals up to Anharmonic Vibrational Properties — •Johannes Hoja, Alexander List, and Adrian Daniel Boese — University of Graz, Graz, Austria

Accurate modeling of molecular crystals is crucial for drug design and crystal engineering. However, periodic density functional calculations using hybrid functionals are often prohibitively expensive for practically relevant molecular crystals. One way of circumventing expensive periodic calculations is the usage of a subtractive embedding scheme, where the periodic calculation is only performed with a lower-cost method and then monomer energies and multimer interaction energies are replaced by those of the high-level method. Herein, we present such a multimer embedding approach for energies, structures, and vibrational properties of molecular crystals containing up to trimer interactions [1]. We evaluate this approach for the X23 benchmark set by approximating periodic PBE0+MBD by embedding multimers into less expensive PBE+MBD calculations. We show that trimer interactions are crucial for approximating lattice energies within 1 kJ/mol and cell volumes within 1 %. Harmonic vibrational free energies can already be approximated within 1 kJ/mol at the monomer or dimer level. Finally, we also utilize this embedding approach to incorporate anharmonic effects via second-order vibrational perturbation theory (VPT2) calculations of monomers and dimers.

[1] J. Hoja, A. List, A.D. Boese, J. Chem. Theory Comput., in press, DOI: 10.1021/acs.jctc.3c01082.

Keywords: density functional theory; subtractive multimer embedding; molecular crystals; lattice energies; vibrational properties