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Intracule functional models. IV. Basis set effects.

Jason K Pearson1, Deborah L Crittenden, Peter M W Gill

  • 1Research School of Chemistry, Australian National University, ACT 0200, Australia.

The Journal of Chemical Physics
|May 2, 2009
PubMed
Summary
This summary is machine-generated.

Basis set effects on electron intracules are minimal. Correlation energies calculated using the dot intracule ansatz show remarkable insensitivity to basis set quality, with low mean absolute errors across various computational chemistry basis sets.

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Area of Science:

  • Computational Chemistry
  • Quantum Chemistry
  • Theoretical Chemistry

Background:

  • Intracules provide insights into electron correlation.
  • Accurate calculation of correlation energies is crucial in quantum chemistry.
  • The choice of basis set can significantly impact computational results.

Purpose of the Study:

  • To investigate the influence of different basis sets on position and dot intracules.
  • To evaluate the sensitivity of correlation energies derived from the dot intracule ansatz to basis set quality.
  • To assess the accuracy of the dot intracule ansatz across a range of basis sets.

Main Methods:

  • Calculation of position and dot intracules for atomic and molecular systems.
  • Utilized unrestricted Hartree-Fock wave functions expanded in various basis sets (STO-3G to cc-pV5Z).
  • Employed the dot intracule ansatz for correlation energy estimation.

Main Results:

  • Basis set effects on intracules were found to be small.
  • Correlation energies from the dot intracule ansatz demonstrated remarkable insensitivity to basis set quality.
  • Mean absolute errors in correlation energies across the G1 data set were consistently within 2 mE(h) for all tested basis sets.

Conclusions:

  • The dot intracule ansatz offers a robust method for estimating correlation energies, largely independent of basis set choice.
  • Computational efficiency can be maintained without significant loss of accuracy in correlation energy calculations.
  • This finding supports the utility of intracule-based methods in quantum chemical studies.