<div>
<div>
<div>
<p>We report a production-level implementation of equation-of-motion coupled-cluster method with double electron-
attaching EOM operators of 2p and 3p1h types, EOM-DEA-CCSD. This ansatz, suitable for treating electronic structure patterns that can be described as two-electrons-in-many orbitals, represents a useful addition to EOM-CC family
of methods. We analyze the performance of EOM-DEA-CCSD for energy differences and molecular properties. By
considering reduced quantities, such as state and transition one-particle density matrices, we can compare EOM-DEA-
CCSD wave-functions with wave-functions computed by other EOM-CCSD methods. The benchmarks illustrate that
EOM-DEA-CCSD capable of treating diradicals, bond-breaking, and some types of conical intersection.
</p>
</div>
</div>
</div>