User profiles for Omar Valsson

Omar Valsson

University of North Texas
Verified email at unt.edu
Cited by 2869

Enhancing important fluctuations: Rare events and metadynamics from a conceptual viewpoint

O Valsson, P Tiwary, M Parrinello - Annual review of physical …, 2016 - annualreviews.org
Atomistic simulations play a central role in many fields of science. However, their usefulness
is often limited by the fact that many systems are characterized by several metastable states …

Enhanced sampling methods for molecular dynamics simulations

J Hénin, T Lelièvre, MR Shirts, O Valsson… - arXiv preprint arXiv …, 2022 - arxiv.org
Enhanced sampling algorithms have emerged as powerful methods to extend the utility of
molecular dynamics simulations and allow the sampling of larger portions of the configuration …

Promoting transparency and reproducibility in enhanced molecular simulations

…, J Šponer, DWH Swenson, P Tiwary, O Valsson… - Nature …, 2019 - hal.science
Molecular dynamics (MD) simulations have become an important tool for characterizing
mechanisms underlying complex processes, interpreting experimental measurements, and …

Variational approach to enhanced sampling and free energy calculations

O Valsson, M Parrinello - Physical review letters, 2014 - APS
The ability of widely used sampling methods, such as molecular dynamics or Monte Carlo
simulations, to explore complex free energy landscapes is severely hampered by the …

Electronic excitations of simple cyanine dyes: reconciling density functional and wave function methods

R Send, O Valsson, C Filippi - Journal of chemical theory and …, 2011 - ACS Publications
The simplest cyanine dye series [H 2 N(CH) n NH 2 ] + with n = 1, 3, 5, 7, and 9 appears to
be a challenge for all theoretical excited-state methods since the experimental spectra are …

Photoisomerization of model retinal chromophores: insight from quantum monte carlo and multiconfigurational perturbation theory

O Valsson, C Filippi - Journal of Chemical Theory and …, 2010 - ACS Publications
We present a systematic investigation of the structural relaxation in the excited state of
model retinal chromophores in the gas phase using the complete-active-space self-consistent …

Enhancing entropy and enthalpy fluctuations to drive crystallization in atomistic simulations

PM Piaggi, O Valsson, M Parrinello - Physical review letters, 2017 - APS
Crystallization is a process of great practical relevance in which rare but crucial fluctuations
lead to the formation of a solid phase starting from the liquid. As in all first order first …

Rhodopsin absorption from first principles: Bypassing common pitfalls

O Valsson, P Campomanes, I Tavernelli… - Journal of chemical …, 2013 - ACS Publications
Bovine rhodopsin is the most extensively studied retinal protein and is considered the
prototype of this important class of photosensitive biosystems involved in the process of vision. …

State-specific embedding potentials for excitation-energy calculations

C Daday, C König, O Valsson… - Journal of chemical …, 2013 - ACS Publications
Embedding potentials are frequently used to describe the effect of an environment on the
electronic structure of molecules in larger systems, including their excited states. If such …

Frequency adaptive metadynamics for the calculation of rare-event kinetics

Y Wang, O Valsson, P Tiwary, M Parrinello… - The Journal of …, 2018 - pubs.aip.org
The ability to predict accurate thermodynamic and kinetic properties in biomolecular systems
is of both scientific and practical utility. While both remain very difficult, predictions of …