_version_ 1866915598409138176
author Folkestad, Sarai Dery
Kjønstad, Eirik F.
Paul, Alexander C.
Myhre, Rolf H.
Alessandro, Riccardo
Angelico, Sara
Balbi, Alice
Barlini, Alberto
Bianchi, Andrea
Cappelli, Chiara
Castagnola, Matteo
Coriani, Sonia
Moutaoukal, Yassir El
Giovannini, Tommaso
Goletto, Linda
Haugland, Tor S.
Hollas, Daniel
Høyvik, Ida-Marie
Lexander, Marcus T.
Lipovec, Doroteja
Marrazzini, Gioia
Moitra, Torsha
Os, Ylva
Paul, Regina
Pedersen, Jacob
Rinaldi, Matteo
Riso, Rosario R.
Roet, Sander
Ronca, Enrico
Rossi, Federico
Sannes, Bendik S.
Schnack-Petersen, Anna Kristina
Skeidsvoll, Andreas S.
Stoll, Leo
Thiam, Guillaume
Trabski, Jan Haakon M.
Koch, Henrik
author_facet Folkestad, Sarai Dery
Kjønstad, Eirik F.
Paul, Alexander C.
Myhre, Rolf H.
Alessandro, Riccardo
Angelico, Sara
Balbi, Alice
Barlini, Alberto
Bianchi, Andrea
Cappelli, Chiara
Castagnola, Matteo
Coriani, Sonia
Moutaoukal, Yassir El
Giovannini, Tommaso
Goletto, Linda
Haugland, Tor S.
Hollas, Daniel
Høyvik, Ida-Marie
Lexander, Marcus T.
Lipovec, Doroteja
Marrazzini, Gioia
Moitra, Torsha
Os, Ylva
Paul, Regina
Pedersen, Jacob
Rinaldi, Matteo
Riso, Rosario R.
Roet, Sander
Ronca, Enrico
Rossi, Federico
Sannes, Bendik S.
Schnack-Petersen, Anna Kristina
Skeidsvoll, Andreas S.
Stoll, Leo
Thiam, Guillaume
Trabski, Jan Haakon M.
Koch, Henrik
contents The eT program is an open-source electronic structure program with emphasis on performance and modularity. As its name suggests, the program features extensive coupled cluster capabilities, performing well compared to other electronic structure programs, and, in some cases, outperforming commercial alternatives. However, eT is more than a coupled cluster program; other models based on wave function theory (such as full and reduced space configuration interaction and a variety of self-consistent field models) and density functional theory are supported. The second major release of the program, eT 2.0, has specialized functionality for strong light-matter coupling conditions. In addition, it includes a wide range of optimizations and algorithmic improvements, as well as new capabilities for exploring potential energy surfaces and for modeling experiments in the UV and X-ray regimes. Molecular gradients are now available at the coupled cluster level, and high-accuracy spectroscopic simulations are available at reduced computational cost within the multilevel coupled cluster and multiscale frameworks. We present the modifications to the program since its first major release, eT 1.0, highlighting some notable new features and demonstrating the performance of the new version relative to the first release and to other established electronic structure programs.
format Preprint
id arxiv_https___arxiv_org_abs_2510_24156
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle eT 2.0: An efficient open-source molecular electronic structure program
Folkestad, Sarai Dery
Kjønstad, Eirik F.
Paul, Alexander C.
Myhre, Rolf H.
Alessandro, Riccardo
Angelico, Sara
Balbi, Alice
Barlini, Alberto
Bianchi, Andrea
Cappelli, Chiara
Castagnola, Matteo
Coriani, Sonia
Moutaoukal, Yassir El
Giovannini, Tommaso
Goletto, Linda
Haugland, Tor S.
Hollas, Daniel
Høyvik, Ida-Marie
Lexander, Marcus T.
Lipovec, Doroteja
Marrazzini, Gioia
Moitra, Torsha
Os, Ylva
Paul, Regina
Pedersen, Jacob
Rinaldi, Matteo
Riso, Rosario R.
Roet, Sander
Ronca, Enrico
Rossi, Federico
Sannes, Bendik S.
Schnack-Petersen, Anna Kristina
Skeidsvoll, Andreas S.
Stoll, Leo
Thiam, Guillaume
Trabski, Jan Haakon M.
Koch, Henrik
Chemical Physics
The eT program is an open-source electronic structure program with emphasis on performance and modularity. As its name suggests, the program features extensive coupled cluster capabilities, performing well compared to other electronic structure programs, and, in some cases, outperforming commercial alternatives. However, eT is more than a coupled cluster program; other models based on wave function theory (such as full and reduced space configuration interaction and a variety of self-consistent field models) and density functional theory are supported. The second major release of the program, eT 2.0, has specialized functionality for strong light-matter coupling conditions. In addition, it includes a wide range of optimizations and algorithmic improvements, as well as new capabilities for exploring potential energy surfaces and for modeling experiments in the UV and X-ray regimes. Molecular gradients are now available at the coupled cluster level, and high-accuracy spectroscopic simulations are available at reduced computational cost within the multilevel coupled cluster and multiscale frameworks. We present the modifications to the program since its first major release, eT 1.0, highlighting some notable new features and demonstrating the performance of the new version relative to the first release and to other established electronic structure programs.
title eT 2.0: An efficient open-source molecular electronic structure program
topic Chemical Physics
url https://arxiv.org/abs/2510.24156