This article summarizes technical advances contained in the fifth major release of the Q-
Chem quantum chemistry program package, covering developments since 2015. A …

Time‐Dependent Density Functional Theory (TD‐DFT) has become the most widely‐used
theoretical approach to simulate the optical properties of both organic and inorganic …

DFTB+ is a versatile community developed open source software package offering fast and
efficient methods for carrying out atomistic quantum mechanical simulations. By …

Singlet exciton fission transforms a molecular singlet excited state into two triplet states,
each with half the energy of the original singlet. In solar cells, it could potentially double the …

Among the diverse and ever-expanding array of approaches to the electronic structure
problem, the rise of approximate density functional theory (DFT) as the method of choice for …

We present a general approach to converge excited state solutions to any quantum
chemistry orbital optimization process, without the risk of variational collapse. The resulting …

In multicomponent quantum chemistry, more than one type of particle is treated quantum
mechanically with either density functional theory or wave function based methods. In …

Orbital optimization is crucial when using a non-Aufbau Slater determinant that involves
promotion of an electron from a (nominally) occupied molecular orbital to an unoccupied …

We present the use of the recently developed square gradient minimization (SGM) algorithm
for excited-state orbital optimization to obtain spin-pure restricted open-shell Kohn–Sham …

Rapid advances in chemical synthesis and fabrication techniques have led to a boost in
manufacturing and design of novel nanostructured materials that exhibit unique and often …