The SS-FNO-IP-EOM-CCSD* described above is implemented in our in-house software package BAGH . BAGH is written primarily in Python with the computational bottleneck steps written in Fortran and Cython, and it can perform wave-function-based calculations based on Schrodinger and Dirac equations. BAGH relies on other software packages for the generation of one and two electron integrals and is currently interfaced with PySCF , GAMESS-US and DIRAC . The results presented in this manuscript are calculated using the PySCF interface of BAGH.