An overview of the Temperature Programmed Molecular Dynamics (TPMD) method - 4
Channel: Abhijit Chatterjee
Date: 2021-05-25

The temperature-programmed molecular dynamics (TPMD) method [1] is a rare-event acceleration technique that provides a convenient way of estimating the effective rate constants and the Arrhenius parameters of kinetic pathways even in situations where the underlying landscape is rugged. In this talk, I will present some of the new advances in the TPMD method. In particular, I will talk about a new variation of the TPMD method that employs finite time MD calculations in order to speed-up thermally activated events from a particular state of the system. Kinetic pathways are sought from a collection of states without any prior knowledge of these pathways. Since kinetic pathways are selected with a probability that is proportional to their rate constants, we find that slow pathways with small pre-exponential factors and large activation barriers are rarely sampled with TPMD. We introduce a procedure to overcome this limitation by employing bias potentials. This additional feature in the TPMD method dramatically improves its ability to estimate Arrhenius parameters. Examples of the variation of the TPMD method are provided for metal surface diffusion in presence of solvent.

1. S. Shivpuje, M. Kumawat, A Chatterjee, Computer Physics Communications, 262, 107828 (2021)