Theoretical study of structure and thermodynamic properties of YC2

Ab initio complete active space self-consistent field (CASSCF) followed by configuration interaction computations that included up to 530000 configurations are carried out on YC2. Dissociation and atomization energies for the theoretically determined structure agree with the experimental studies of the thermodynamic properties of YC2. The calculated Gibbs energy functions and heat content functions for YC2 support experimental studies, despite the difference between the theoretically determined structure and the assumed structure.