1.2k citations · 2.7k across the 53 of their papers we have counts for
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Automatic generation of exchange-correlation response kernels
Susi Lehtola
Computing density-functional response properties requires contracting derivatives of the exchange--correlation (xc) energy with perturbed densities on a grid. While the xc function…
libwignernj: a reusable C/C++/Fortran/Python library for exact Wigner symbols and related coefficients
Susi Lehtola
We describe libwignernj, a freely available, BSD-licensed library that evaluates Wigner 3j, 6j, and 9j symbols, Clebsch--Gordan, Racah , and Fano coefficients, and Gaunt coe…
Real Quantum Chemistry With Complex Orbitals
Hugo Åström, Susi Lehtola
We follow up our study of basis set truncation errors for atoms in magnetic fields [Åström and Lehtola, J. Phys. Chem. A, 2023, 127, 10872]. Our previous study employed an approxim…
Atomic Confinement Potentials and the Generation of Numerical Atomic Orbitals
Hugo Åström, Susi Lehtola
We aim to develop novel reusable open source infrastructure [Lehtola, J. Chem. Phys. 159, 180901 (2023)] for numerical atomic orbitals (NAOs). Soft confinement potentials are typic…
OpenOrbitalOptimizer -- a reusable open source library for self-consistent field calculations
Susi Lehtola, Lori A. Burns
According to the modern paradigms of software engineering, standard tasks are best accomplished by reusable open source libraries. We describe OpenOrbitalOptimizer: a reusable open…
Repulsive interatomic potentials calculated at three levels of theory
Kai Nordlund, Susi Lehtola, Gerhard Hobler
The high-energy repulsive interaction between nuclei at distances much smaller than the equilibrium bond length is the key quantity determining the nuclear stopping power and atom…
Review of the finite difference Hartree-Fock method for atoms and diatomic molecules, and its implementation in the x2dhf program
Jacek Kobus, Susi Lehtola
We present an extensive review of the two-dimensional finite difference Hartree--Fock (FD HF) method, and present its implementation in the newest version of X2DHF, the FD HF progr…
A call to arms: making the case for more reusable libraries
Susi Lehtola
The traditional foundation of science lies on the cornerstones of theory and experiment. Theory is used to explain experiment, which in turn guides the development of theory. Since…
Reproducibility of density functional approximations: how new functionals should be reported
Susi Lehtola, Miguel A. L. Marques
Density functional theory is the workhorse of chemistry and materials science, and novel density functional approximations (DFAs) are published every year. To become available in p…
Automatic Generation of Accurate and Cost-efficient Auxiliary Basis Sets
Susi Lehtola
We have recently discussed an algorithm to automatically generate auxiliary basis sets (ABSs) of the standard form for density fitting (DF) or resolution-of-the-identity (RI) calcu…
On the accuracy of a recent regularized nuclear potential
Susi Lehtola
F. Gygi recently suggested an analytic, norm-conserving, regularized nuclear potential to enable all-electron plane-wave calculations [J. Chem. Theory Comput. 2023, 19, 1300--1309]…
Meta-GGA density functional calculations on atoms with spherically symmetric densities in the finite element formalism
Susi Lehtola
Density functional calculations on atoms are often used for determining accurate initial guesses as well as generating various types of pseudopotential approximations and efficient…
How good are recent density functionals for ground and excited states of one-electron systems?
Sebastian Schwalbe, Kai Trepte, Susi Lehtola
Sun et al. [J. Chem. Phys. 144, 191101 (2016)] suggested that common density functional approximations (DFAs) should exhibit large energy errors for excited states as a necessary c…
Many recent density functionals are numerically ill-behaved
Susi Lehtola, Miguel A. L. Marques
Most computational studies in chemistry and materials science are based on the use of density functional theory. Although the exact density functional is unknown, several density f…
Chemical bonding theories as guides for self-interaction corrected solutions: multiple local minima and symmetry breaking
Kai Trepte, Sebastian Schwalbe, Simon Liebing +5
Fermi--Löwdin orbitals (FLO) are a special set of localized orbitals, which have become commonly used in combination with the Perdew--Zunger self-interaction correction (SIC) in th…
Efficient implementation of the superposition of atomic potentials initial guess for electronic structure calculations in Gaussian basis sets
Susi Lehtola, Lucas Visscher, Eberhard Engel
The superposition of atomic potentials (SAP) approach has recently been shown to be a simple and efficient way to initialize electronic structure calculations [S. Lehtola, J. Chem.…
Polarized Gaussian basis sets from one-electron ions
Susi Lehtola
We demonstrate that basis sets suitable for electronic structure calculations can be obtained from simple accuracy considerations for the hydrogenic one-electron ions …
On the accurate reproduction of strongly repulsive interatomic potentials
Susi Lehtola
Knowledge of the repulsive behavior of potential energy curves at is necessary for understanding and modeling irradiation processes of practical interest. is…
An overview of self-consistent field calculations within finite basis sets
Susi Lehtola, Frank Blockhuys, Christian Van Alsenoy
A uniform derivation is presented of the self-consistent field equations in a finite basis set. Both restricted and unrestricted Hartree-Fock (HF) theory as well as various density…
CASSCF with Extremely Large Active Spaces using the Adaptive Sampling Configuration Interaction Method
Daniel S. Levine, Diptarka Hait, Norm M. Tubman +3
The complete active space self-consistent field (CASSCF) method is the principal approach employed for studying strongly correlated systems. However, exact CASSCF can only be perfo…
Fully numerical calculations on atoms with fractional occupations. Range-separated exchange functionals
Susi Lehtola
A recently developed finite element approach for fully numerical atomic structure calculations [S. Lehtola, Int. J. Quantum Chem. 119, e25945 (2019)] is extended to the description…
PyFLOSIC: Python-based Fermi-Löwdin orbital self-interaction correction
Sebastian Schwalbe, Lenz Fiedler, Jakob Kraus +3
We present PyFLOSIC, an open-source, general-purpose Python implementation of the Fermi-Löwdin orbital self-interaction correction (FLO-SIC), which is based on the Python simulatio…