Introduction to the VB Workshop
Context and motivation
Valence Bond (VB) theory provides an unmatched intimate connection between the accurate quantum theory and chemical concepts - models which chemists use for ‘thinking’ about chemistry (localized electron pairs, Lewis model, resonance and hybridization...), and thus is a novel method for the simulation of molecules compared with the much popular Molecular Orbital (MO) Theory.
Despite its unique interpretative capabilities, VB theory and its various implemented methods are still used by a still limited community of chemists. Moreover, this beautiful theory is barely taught anymore in advanced university courses. This is because starting from the 1970s, accurate and efficient electronic structure methods that could be implemented were largely based on MO Theory, which utilizes orthogonal orbitals. These methods have been continuously improved and very intensively used to solve many problems in chemistry, physics and biology. At the same time, the development of accurate ab initio VB methods has been significantly impeded by algorithmic difficulties, mostly related to the non-orthogonal problem at the roots of VB theory.
Very recently several methods and algorithmic breakthroughs have been accomplished, which, together with the ever-increasing computational resources, allow nowadays the application of accurate VB methods to a wide range of systems and chemical problems. In particular, QM(VB)/MM coupling now makes VB a novel simulation method for molecules (see here or there for instances). However, future progress in methods and algorithms, as well as the up rise of VB theory among chemists, will depend on the capacity of the VB community to join forces and extend to impact the large community of chemists
Purposes
Following these motivations, the purposes of this workshop will be three-fold :
- to be a meeting ground for chemists from diverse scientific communities, whose interest are related with aspects of ab initio VB theory,
- to stimulate further developments in VB methods and algorithms, new applications of VB theory to chemical problems, and new collaborations,
- to guide newcomers to ab initio Valence Bond to learn the necessary basics of the theory and start using some of the available VB codes (especially the XMVB and BLW programs).
Overview
Considering its purposes, the workshop will contains :
- plenary lectures on Valence Bond theory, methods, and related models,
- extension lectures to provide connections between VB and other related wave function and interpretative methods
- short talks given by participants on a topic relevant to VB theory
- ample space dedicated to free discussions
- "hands-on" lab : basic initiation to the XMVB and BLW programs