Wavefunction based calculations on 1-Sm, 1-Eu, 1-Tb, 1-Dy, 1-Ho, 1-Er, 1-Tm, and 1-Yb were performed using the unoptimized atomic coordinates obtained from the X-ray crystal structures. All calculations were performed using complete-active space self-consistent field spin-orbit (CASSCF-SO) method in OpenMolcas on the Spartan computational platform. We employ the necessary ANO-RCC basis set (which incorporate relativistic corrections) with the literature triple-zeta polarized (TZP) basis set was applied to the RE centre, double-zeta (DZP) polarized was applied to all coordinating atoms, and the remaining atoms, a double-zeta (DZ) basis set was applied. The active space in all cases was the 4f orbitals with the respective RE 3+ electron count. In all cases the quantization axis is fixed to the C3 crystallographic axis to calculate wave function and g-tensor anisotropy for Kramer's doublets (KD) (and pseudo-KD) states.