Martin Head-Gordon

TL;DR: Specific developments discussed include fast methods for density functional theory calculations, linear scaling evaluation of energies, NMR chemical shifts and electric properties, fast auxiliary basis function methods for correlated energies and gradients, equation-of-motion coupled cluster methods for ground and excited states, geminal wavefunctions, embedding methods and techniques for exploring potential energy surfaces.

TL;DR: A summary of the technical advances that are incorporated in the fourth major release of the Q-Chem quantum chemistry program is provided in this paper, covering approximately the last seven years, including developments in density functional theory and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces.

TL;DR: In this article, the activation energy of the A1C02 reaction is 2.5 and 3.9 kcal/mol, respectively, while the experimentally estimated heat of reaction is about 5 kcal/molecular.

TL;DR: In this article, the Tamm-Dancoff approximation to time-dependent density functional theory is proposed and implemented for molecular excited states, which yields excitation energies for several closed-and open-shell molecules that are essentially of the same quality as those obtained from time dependent density functional theories itself, when the same exchange correlation functional is used.