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Introducing MPEC: Massively parallel electron correlation.

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A new internally contracted Multi-reference Configuration Interaction Singles and Doubles (i²cMRCISD) program offers improved computational efficiency on parallel computers. This advanced quantum chemistry software enables complex electronic structure calculations with enhanced accuracy and scalability.

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Area of Science:

  • Quantum Chemistry
  • Computational Physics
  • Theoretical Chemistry

Background:

  • Accurate electronic structure calculations are crucial for understanding molecular properties.
  • Existing computational methods face challenges with scalability and accuracy for complex systems.
  • The need for efficient, parallelized quantum chemistry software is growing.

Purpose of the Study:

  • To introduce a novel, parallelized program for internally contracted Multi-reference Configuration Interaction Singles and Doubles (i²cMRCISD) calculations.
  • To enhance the capabilities of quantum chemical computations on distributed memory systems.
  • To provide a robust tool for advanced electronic structure investigations.

Main Methods:

  • Development of a new i²cMRCISD program optimized for distributed memory parallel computers.
  • Implementation of support for large Gaussian basis sets (ℓ > 6) and scalar relativistic effects (spin-free).
  • Inclusion of features for various electronic state convergences, Rydberg orbital determination, and analytic Born-Oppenheimer corrections.

Main Results:

  • The developed i²cMRCISD program demonstrates good scaling properties across multiple cores and nodes.
  • The software supports a wide range of advanced computational features, including spin-orbit coupling and Breit interaction.
  • Successful implementation of analytic Born-Oppenheimer diagonal and second-order corrections.

Conclusions:

  • The new i²cMRCISD program offers a significant advancement in computational efficiency and capability for quantum chemistry.
  • Its parallel design and comprehensive features make it suitable for tackling complex electronic structure problems.
  • The program is available for researchers, facilitating further advancements in theoretical chemistry and related fields.