New Developments of Variationally Enhanced Sampling

Variationally enhanced sampling (VES) is a collective variable based enhanced sampling method where we construct the external bias potential via a variational principle by minimizing a convex functional [1,2]. We can employ VES to obtain both free energy landscapes and kinetics of rare events. The method is available in the VES code [3], an open-source library for the PLUMED 2 plugin [4], allowing usage of the technique in a wide range of molecular dynamics codes.

In this talk, I will present two new developments of VES. The first development is the implementation of wavelet-based bias potentials that gives better performance than localized basis functions. The second development is an extension for biasing permutationally invariant local collective variables. We show how we can use this extension to accelerate phase-transitions in materials composed of identical building blocks.

[1] O. Valsson and M. Parrinello, Phys. Rev. Lett. 113 090601 (2014) [doi: 10.1103/ PhysRevLett.113.090601]
[2] O. Valsson and M. Parrinello, Handbook of Materials Modeling, Methods: Theory and Modeling (Vol. I) (2020) [doi: 10.1007/978-3-319-42913-7_50-1]
[3] http://www.ves-code.org
[4] http://www.plumed.org