Electronic structure of CaCO3: A Compton scattering study

In the present work, we have studied electron momentum density of CaCO3 using a Compton scattering technique. The experiment has been performed using a 100 mCi 241Am (59.54 keV) Compton spectrometer. The experimental data have been interpreted in terms of theoretical Compton profiles. To compute the theoretical momentum densities, energy bands and density of states, we have used linear combination of atomic orbitals method as embodied in CRYSTAL09 code. We have used local density approximation, generalized gradient approximation (GGA) and second order GGA (SOGGA) within the frame work of density functional theory. It is seen that the GGA gives a better agreement with the experimental data than other approximations. We have also discussed the energy bands and density of states of CaCO3.

► Experimental Compton profile (CP) of CaCO3 is measured using 241Am source. ► Experimental CP is compared with DFT profiles. ► Energy bands and density of states are also computed using DFT schemes. ► Band gap is deduced from the different DFT schemes.