Generalized Valence Bond Perfect-Pairing Made Versatile Through Electron-Pairs Embedding

Electron wave packet modeling of chemical bonding: Floating and breathing minimal packets with perfect-pairing valence-bond spin coupling

Pseudospectral contracted configuration interaction from a generalized valence bond reference

Substantial progress has been made in the development of accurate self-consistent multiconfigurational (MCSCF) wave functions.’ In particular, it has been shown that multireference CI (MRCI)’ and more recently multireference perturbation theory (MRPT)3’6 using these MCSCF references leads to quiti accurate predictions for a wide variety of molecular properties. However, the computational cost o...

Generalized valence bond molecular dynamics at constant temperature

The Nose! ± Hoover chain thermostat of Martyna, Klein and Tuckerman has been adapted to work with our generalized valence bond ab initio molecular dynamics (AIMD) method, allowing us to perform AIMD in the canonical ensemble (constant number of particles, temperature, and volume). The canonical ensemble is ideal for simulated annealing, which can be used to ® nd global potential energy minima. ...

Self-Consistent Procedures for Generalized Valence Bond Wavefunctions. Applications

Methods of efficiently optimizing the orbitals of generalized valence bond (GVB) wavefunctions are discussed and applied to LiH, BH, H3, H,O, C6Hs, and o,. The strong orthogonality and perfect pairing restrictions are tested for the X 1::!:+ state of LiH, the X 1::!:+, a 3II, and A 1II states of BH, and the H2+ D;::::: H + HD exchange reaction. The orbitals of H,O and C2H6 naturally localize in...

Generalized valence bond wave functions in quantum Monte Carlo.

We present a technique for using quantum Monte Carlo (QMC) to obtain high quality energy differences. We use generalized valence bond (GVB) wave functions, for an intuitive approach to capturing the important sources of static correlation, without needing to optimize the orbitals with QMC. Using our modifications to Walker branching and Jastrows, we can then reliably use diffusion quantum Monte...