Ab initio investigations of the perovskite and K_2MF_4 phases in the Cs-Ca-H system

摘要

Deriving the energy-volume equation of state within DFT for CsCaH_3 and Cs_2CaH_4 has allowed predicting significant changes within the ionic behavior of hydrogen. In Cs_2CaH_4, apical H1 and equatorial H2 are found as less and more ionic respectively as compared to the perovskite hydride. This leads to a larger overall binding both from energy differences and chemical bonding analysis.