EncyclopedAI

Retrieving "Configuration Interaction" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

  1. Numerical Methods In Chemistry

    Linked via "Configuration Interaction (CI)"

    Correlation energy must be recovered post-HF using post-HF methods, which are inherently numerical integration schemes .
    Configuration Interaction (CI) and Truncation Errors
    Full Configuration Interaction (FCI) is computationally intractable for all but the smallest systems, scaling factorially with system size. Truncated CI methods (CISD, CEPA) rely on iteratively calculating and diagonalizin…

  2. Numerical Methods In Chemistry

    Linked via "CI methods"

    Configuration Interaction (CI) and Truncation Errors
    Full Configuration Interaction (FCI) is computationally intractable for all but the smallest systems, scaling factorially with system size. Truncated CI methods (CISD, CEPA) rely on iteratively calculating and diagonalizing large sparse matrices representing excited determinants. A known numerical artifact in CI calculations on molecules containing [silicon (Si)](/…

  3. Potential Energy Surface

    Linked via "Configuration Interaction (CI)"

    Quantum Chemical Methods
    Quantum chemistry calculates the electronic energy $E_e$ at discrete points (geometries) on the surface. Common methods include Hartree-Fock (HF), Configuration Interaction (CI), and Density Functional Theory (DFT).
    Table 1: Comparison of PES Sampling Techniques

  4. Quantum Chemistry

    Linked via "CI methods"

    To account for the correlation energy, various post-HF methods are employed:
    Configuration Interaction (CI): The true wavefunction is represented as a linear combination of the HF ground state determinant and excited state determinants (constructed from applying excitation operators to the reference determinant). Full CI (FCI) is exact within the basis set limit but com…

  5. Quantum Chemistry

    Linked via "CISD"

    Configuration Interaction (CI): The true wavefunction is represented as a linear combination of the HF ground state determinant and excited state determinants (constructed from applying excitation operators to the reference determinant). Full CI (FCI) is exact within the basis set limit but computationally intractable for most chemical systems. Truncated [CI methods](/entries/configuration-interaction/…