Publications by Konstantin Karandashev

A combined on-the-fly/interpolation procedure for evaluating energy values needed in molecular simulations

We propose an algorithm for molecular dynamics or Monte Carlo simulations that uses an interpolation procedure to estimate potential energy values from energies and gradients evaluated previously at points of a simplicial mesh. We chose an interpolation pr ...

2019

Accelerating equilibrium isotope effect calculations. II. Stochastic implementation of direct estimators

Jiri Vanicek, Konstantin Karandashev

2019

Accelerating path integral evaluation of equilibrium and kinetic isotope effects

Konstantin Karandashev

Investigating the effect of isotope substitution on equilibrium and kinetic properties of molecules has become an important tool for estimating the importance of nuclear quantum effects. In this work, we discuss calculating both equilibrium and kinetic iso ...

EPFL2018

Accelerating equilibrium isotope effect calculations. I. Stochastic thermodynamic integration with respect to mass

Jiri Vanicek, Konstantin Karandashev

Accurate path integral Monte Carlo or molecular dynamics calculations of isotope effects have until recently been expensive because of the necessity to reduce three types of errors present in such calculations: statistical errors due to sampling, path inte ...

American Institute of Physics2017

Kinetic isotope effects and how to describe them

Jiri Vanicek, Konstantin Karandashev

We review several methods for computing kinetic isotope effects in chemical reactions including semiclassical and quantum instanton theory. These methods describe both the quantization of vibrational modes as well as tunneling and are applied to the ⋅H + H ...

2017

Accelerating quantum instanton calculations of the kinetic isotope effects

Jiri Vanicek, Konstantin Karandashev

Path integral implementation of the quantum instanton approximation currently belongs among the most accurate methods for computing quantum rate constants and kinetic isotope effects, but its use has been limited due to the rather high computational cost. ...

American Institute of Physics2015