Negative thermal expansion of ScF 3 : first principles vs empirical molecular dynamics

The calculations were performed on the Paul Scherrer Institute cluster Merlin4, HPC resources of the Swiss National Supercomputing Centre in Lugano (project ID s626) as well as at the Latvian SuperCluster (LASC). Authors are greatly indebted to S. Ali, D. Gryaznov, R.A. Evarestov, M. Isupova, A. Kalinko, V. Kashcheyevs, V. Pankratov, S. Piskunov, A. I. Popov, J. Purans, F. Rocca, L. Shirmane, P. Zˇguns, and Yu. F. Zhukovskii for many stimulating discussions. Financial support provided by project No. 1.1.1.2/VIAA/l/16/147 (1.1.1.2/16/I/001) under the activity “Post-doctoral research aid” realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged.