The positions of the interstitial oxygen atoms in LiYF4 crystal were simulated by

computer technologies. It was found that the total energy of cluster was low when

interstitial oxygen atoms exist around the Li+ ion. Basing on the computer results,

the electronic structures of perfect LiYF4 and the LiYF4 containing interstitial

oxygen atoms with the lattice structure optimized were studied within the

framework of the density functional theory. By analyzing the calculated results it

can be concluded that an interstitial oxygen atom could combine with formal lattice

fluorine ions forming molecular ions, which cause the 260nm absorption band.

Ab Initio Study Electronic Structures of LiYF4 Crystal Containing Interstitial

Oxygen Atoms. J.Yin, Q.Zhang, T.Liu, X.Guo, M.Song, X.Wang, H.Zhang:

Nuclear Instruments and Methods in Physics Research B, 2009, 267[1], 74-8