Real-time electronic structure methods provide an unprecedented view of electron dynamics
and ultrafast spectroscopy on the atto-and femtosecond time scale with vast potential to yield …

We review the current state of reduced‐scaling electron correlation methods, particularly
coupled‐cluster theory for the simulation and prediction of molecular response properties …

We report the first implementation of real-time time-dependent density functional theory (RT-
TDDFT) at the relativistic four-component level of theory. In contrast to the perturbative linear …

In this paper we present a time-domain time-dependent density functional theory (TDDFT)
approach to calculate frequency-dependent polarizability and hyperpolarizabilities. In this …

Recent developments in nonlinear imaging microscopy show the need to implement new
theoretical tools, which are able to characterize nonlinear optical properties in an efficient …

Theoretical methods able to screen large sets (eg, conformers) of possibly large compounds
are needed in many typical quantum chemistry applications. For this purpose, we here …

The Liouville–von Neumann equation based on the four-component matrix Dirac–Kohn–
Sham Hamiltonian is transformed to a quasirelativistic exact two-component (X2C) form and …

The search for fluorescent proteins with large two-photon absorption (TPA) cross-sections
and improved brightness is required for their efficient use in bioimaging. Here, we explored …

This work presents the theoretical background to evaluate two-photon absorption (2PA)
cross-sections in the framework of simplified time-dependent density functional theory (sTD …

We demonstrate that electronic excitations and their transition densities can be obtained
from real-time density functional theory calculations with great accuracy by relating the data …