Anisotropic displacement parameters for molecular crystals from periodic HF and DFT calculations

Content Provider	Semantic Scholar
Author	Madsen, Anders Ø. Civalleri, Bartolomeo Pascale, Fabien Dovesi, Roberto Larsen, Søren
Copyright Year	2008
Abstract	Fully periodic Hartree-Fock and DFT calculations have been used to compute the anisotropic displacement parameters (ADPs) of molecular crystals at di↵erent temperatures by using the CRYSTAL code. Crystalline urea was adopted as a benchmark system to investigate the dependence on basis set and Hamiltonian. The results were compared with ADPs derived from neutron di↵raction experiments. The approach can estimate the internal ADPs, corresponding to the contributions of high-frequency intramolecular vibrations, and for these internal contributions the results are almost independent of the basis set and Hamiltonian. Much larger variations and discrepancies from neutron di↵raction experiments are seen for the external, low-frequency modes, which become dominant at higher temperatures. The approach was then tested on benzene and urotropine. Finally, ADPs of L-alanine were predicted at the B3LYP/631G(d,p) level of theory. PREPRINT: Acta Crystallographica Section A A Journal of the International Union of Crystallography
Starting Page	148
Ending Page	148
Page Count	1
File Format	PDF HTM / HTML
DOI	10.1107/S0108767308095238
Alternate Webpage(s)	https://iris.unito.it/retrieve/handle/2318/138541/164807/ab_initio_adps_aperto.pdf
Alternate Webpage(s)	https://doi.org/10.1107/S0108767308095238
Volume Number	64
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article