English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In this work, we develop a mathematical framework for a SelectedConfiguration Interaction (SCI) algorithm within a bi-orthogonal basis fortranscorrelated (TC) calculations. The bi-orthogonal basis used here serves asthe equivalent of the standard Hartree Fock (HF) orbitals. However, within thecontext of TC, it leads to distinct orbitals for the left and right vectors.Our findings indicate that the use of such a bi-orthogonal basis allows for aproper definition of the frozen core approximation. In contrast, the use of HForbitals results in bad error cancellations for ionization potentials andatomization energies (AE). Compared to HF orbitals, the optimized bi-orthogonalbasis significantly reduces the positive part of the second-order energy (PT2),thereby facilitating the use of standard extrapolation techniques of hermitianSCI. While we did not observe a significant improvement in the convergence ofthe SCI algorithm, this is largely due to the use in the present work of asimple three-body correlation factor introduced in a recent study. Thiscorrelation factor, which depends only on atomic parameters, eliminates theneed for re-optimization of the correlation factor for molecular systems,making its use straightforward and user-friendly. Despite the simplicity ofthis correlation factor, we were able to achieve accurate results on the AE ofa series of 14 molecules in a triple-zeta basis. We also successfully broke adouble bond until the full dissociation limit while maintaining the sizeconsistency property. This work thus demonstrates the potential of theBiO-TC-SCI approach in handling complex molecular systems.

Transcorrelated selected configuration interaction in a bi-orthonormal basis and a cheap three-body correlation factor