Optimization of density fitting auxiliary Slater‐type basis functions for time‐dependent density functional theory

• Published in: Journal of computational chemistry Vol. 43; no. 28; pp. 1923 - 1935
• Main Authors: Medves, Marco, Fronzoni, Giovanna, Stener, Mauro
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 30.10.2022; Wiley Subscription Services, Inc
• Subjects: Absorption spectra; Algorithms; Basis functions; density fitting; Density Functional Theory; Electron density; Functionals; Optimization; TDDFT; Time dependence; TDDFT; density fitting
• ISSN: 0192-8651; 1096-987X; 1096-987X
• DOI: 10.1002/jcc.26992

A new set of auxiliary basis function suitable to fit the induced electron density is presented. Such set has been optimized in order to furnish accurate absorption spectra using the complex polarizability algorithm of time‐dependent density functional theory (TDDFT). An automatic procedure has been set up, able, thanks to the definition of suitable descriptors, to evaluate the resemblance of the auxiliary basis‐dependent calculated spectra with respect to a reference. In this way, it has been possible to reduce the size of the basis set maximizing the basis set accuracy. Thanks to the choice to employ a collection of molecules for each element, such basis has proven transferable to molecules outside the collection. The final sets are therefore much more accurate and smaller than the previously optimized ones and have been already included in the database of the last release of the AMS suite of programs. The availability of the present new set will allow to improve drastically the applicability range of the polTDDFT method with higher accuracy and less computational effort. A new set of auxiliary basis function suitable to fit the induced electron density is presented. Such set has been optimized in order to furnish accurate absorption spectra using the complex polarizability algorithm of time‐dependent density functional theory (TDDFT). An automatic procedure has been set up, able, thanks to the definition of suitable descriptors, to evaluate the resemblance of the auxiliary basis dependent calculated spectra with respect to a reference. The value of the descriptor allows to give a quantitative measure of the goodness of the basis set and is employed to follow it during the reduction and optimization procedures.