The developments of the open-source OpenMolcas chemistry software environment since
spring 2020 are described, with a focus on novel functionalities accessible in the stable …

In this perspective, the various measures of electron correlation used in wave function
theory, density functional theory and quantum information theory are briefly reviewed. We …

The properties of all materials arise largely from the quantum mechanics of their constituent
electrons under the influence of the electric field of the nuclei. The solution of the underlying …

We report cutting edge performance results on a single node hybrid CPU-multi-GPU
implementation of the spin adapted ab initio Density Matrix Renormalization Group (DMRG) …

We present NECI, a state-of-the-art implementation of the Full Configuration Interaction
Quantum Monte Carlo (FCIQMC) algorithm, a method based on a stochastic application of …

Quantum Monte Carlo (QMC) methods are the gold standard for studying equilibrium
properties of quantum many-body systems. However, in many interesting situations, QMC …

The incremental expansion provides a polynomial scaling method for computing electronic
correlation energies. This article details a new algorithm and implementation for the …

We identify and rectify a crucial source of bias in the initiator full configuration interaction
quantum Monte Carlo algorithm. Noninitiator determinants (ie, determinants whose …

We expand upon the recent semi-stochastic adaptation to full configuration interaction
quantum Monte Carlo (FCIQMC). We present an alternate method for generating the …

We present a new approach to calculate excited states with the full configuration interaction
quantum Monte Carlo (FCIQMC) method. The approach uses a Gram-Schmidt procedure …