Equation-of-motion coupled cluster method for high spin double electron attachment calculations

2014 ◽  
Vol 140 (11) ◽  
pp. 114107 ◽  
Author(s):  
Monika Musiał ◽  
Łukasz Lupa ◽  
Stanisław A. Kucharski
2020 ◽  
Author(s):  
Soumi Haldar ◽  
Achintya Kumar Dutta

We have presented a multi-layer implementation of the equation of motion coupled-cluster method for the electron affinity, based on local and pair natural orbitals. The method gives consistent accuracy for both localized and delocalized anionic states. It results in many fold speedup in computational timing as compared to the canonical and DLPNO based implementation of the EA-EOM-CCSD method. We have also developed an explicit fragment-based approach which can lead to even higher speed-up with little loss in accuracy. The multi-layer method can be used to treat the environmental effect of both bonded and non-bonded nature on the electron attachment process in large molecules.<br>


2020 ◽  
Author(s):  
Soumi Haldar ◽  
Achintya Kumar Dutta

We have presented a multi-layer implementation of the equation of motion coupled-cluster method for the electron affinity, based on local and pair natural orbitals. The method gives consistent accuracy for both localized and delocalized anionic states. It results in many fold speedup in computational timing as compared to the canonical and DLPNO based implementation of the EA-EOM-CCSD method. We have also developed an explicit fragment-based approach which can lead to even higher speed-up with little loss in accuracy. The multi-layer method can be used to treat the environmental effect of both bonded and non-bonded nature on the electron attachment process in large molecules.<br>


2020 ◽  
Author(s):  
Sahil Gulania ◽  
Eirik Fadum Kjønstad ◽  
John F. Stanton ◽  
Henrik Koch ◽  
Anna Krylov

<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>


2020 ◽  
Author(s):  
Sahil Gulania ◽  
Eirik Fadum Kjønstad ◽  
John F. Stanton ◽  
Henrik Koch ◽  
Anna Krylov

<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>


2020 ◽  
Author(s):  
Sahil Gulania ◽  
Eirik Fadum Kjønstad ◽  
John F. Stanton ◽  
Henrik Koch ◽  
Anna Krylov

<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>


2016 ◽  
Vol 144 (15) ◽  
pp. 154105 ◽  
Author(s):  
Monika Musiał ◽  
Łukasz Lupa ◽  
Stanisław A. Kucharski

Sign in / Sign up

Export Citation Format

Share Document