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Jiří Brabec1, Jiří Pittner1, Hubertus J J van Dam2

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Area of Science:

  • Quantum Chemistry
  • Computational Physics
  • Theoretical Chemistry

Background:

  • Multireference coupled-cluster (MRCC) theory is crucial for accurately describing complex electronic structures.
  • Existing MRCC implementations face challenges in computational scalability and efficiency.
  • The Jeziorski-Monkhorst exponential ansatz provides a foundation for MRCC methods.

Purpose of the Study:

  • Introduce a novel, general algorithm for multireference coupled-cluster (MRCC) theory.
  • Enhance the computational efficiency and scalability of MRCC calculations.
  • Optimize resource utilization in parallel computing environments for quantum chemistry.

Main Methods:

  • Developed a new algorithm utilizing processor groups for calculating MRCC amplitudes.
  • Each processor group handles equations for a specific subset of references.
  • Implemented flexible assignment of reference-specific conditions to processor groups.

Main Results:

  • Demonstrated improved scalability and reduced computation time for Brillouin-Wigner (BW-MRCCSD) and Mukherjee (Mk-MRCCSD) methods.
  • The algorithm shows significant performance gains compared to previous parallel implementations.
  • Efficient utilization of computing resources was achieved through optimized processor group allocation.

Conclusions:

  • The novel algorithm offers a significant advancement in implementing general multireference coupled-cluster theory.
  • This approach enhances computational efficiency and scalability for demanding quantum chemical calculations.
  • The method provides a flexible and optimized strategy for parallel MRCC computations.