Structure and vibrational frequencies of CaF2 aggregates isolated in a low temperature matrix

The FTIR spectra of molecular CaF 2 were measured in argon matrices at cryogenic temperatures ranging from 10 K to 30K according to the adopted experimental conditions. Infrared absorptions of the simplest aggregates such as the dimer Ca 2 F 4 and the trimer Ca 3 F 6 were identified through experiments and were assigned employing the results of polarizable ion calculations. D 2h and D 2d symmetry structures are proposed for the dimer and the trimer respectively.