Berlin 2024 –
scientific programme
DY 32.30: Poster
Wednesday, March 20, 2024, 15:00–18:00, Poster C
Energy conserving adaptive QM/MM method using an extended Hamiltonian approach — •Marvin Nyenhuis and Nikos Doltsinis — Institute for Solid State Theory, University of Münster, Wilhelm-Klemm-Straße 10, 48149 Münster
We present an extended Hamiltonian formalism that introduces a fictitious switching particle with mass µk which propagates a system between two different potential energy surfaces (Vk−1 → Vk) during a hybrid ab initio (QM) and classical force field (MM) molecular dynamics simulation by mixing both potentials via a switching function g(λk) ∈ [0,1].
| H = | | | + | | | | | | µj λj2 + | | g | ⎛
⎝ | λk | ⎞
⎠ | Vk−1 | ⎛
⎝ | R | ⎞
⎠ |
+ | ⎧
⎨
⎩ | 1−g | ⎛
⎝ | λk | ⎞
⎠ | ⎫
⎬
⎭ | Vk | ⎛
⎝ | R | ⎞
⎠ |
| \ |
| v |
| / |
| Vmix |
|
The Hamiltonian consists of the kinetic energy of all nuclei I∈{1,…,N} with mass MI, kinetic energy of all completed λj , j∈{1,…,(k−1)} and running switching procedures (λk) as well as the mixed potential energy Vmix depending on all nuclear positions R. Each λk is propagated from 0→1 and describes the progress of switching.
Keywords: QMMM calculations; Adaptive switching; Extended Hamiltonian
