Go Green: Selected Configuration Interaction as a More Sustainable Alternative for High Accuracy

Pierre-Francois Loos (1, 2) , Yann Damour (1, 2) , Abdallah Ammar (1, 2) , Michel Caffarel (1, 2) , Fábris Kossoski (2, 1) , Anthony Scemama (1, 2)

1 LCPQ - Laboratoire de Chimie et Physique Quantiques
2 GMO - Groupe THEO (LCPQ)

Recently, a new distributed implementation of the full configuration interaction (FCI) method has been reported (Gao et al., J. Chem Theory Comput. (2024), 10.1021/acs.jctc.3c01190]. Thanks to a hybrid parallelization scheme, the authors were able to compute the exact energy of propane (\ce{C3H8}) in the minimal basis STO-3G. This formidable task involves handling an active space of 26 electrons in 23 orbitals or a Hilbert space of \SI{1.3d12} determinants. This is, by far, the largest FCI calculation reported to date. Here, we illustrate how, from a general point of view, selected configuration interaction (SCI) can achieve microhartree accuracy at a fraction of the computational and memory cost, via a sparse exploration of the FCI space. The present SCI calculations are performed with the \textit{Configuration Interaction using a Perturbative Selection made Iteratively} (CIPSI) algorithm, as implemented in a determinant-driven way in the \textsc{quantum package} software. The present study reinforces the common wisdom that among the exponentially large number of determinants in the FCI space, only a tiny fraction of them significantly contribute to the energy. More importantly, it demonstrates the feasibility of achieving comparable accuracy using more reasonable and sustainable computational resources, hence reducing the ever-growing carbon footprint of computational chemistry.

Domaines: Chimie théorique et/ou physique

Pierre-Francois Loos, Yann Damour, Abdallah Ammar, Michel Caffarel, Fábris Kossoski, et al.. Go Green: Selected Configuration Interaction as a More Sustainable Alternative for High Accuracy. 2024. ⟨hal-04470263⟩