Molcas Forum

moabe

Member

Registered: 2018-06-03

Posts: 23

MEP surface hopping

Hi everybody,

I'm trying to do some calculations with MEP surface hopping method. By starting from root 4 (bright state), a hop happened to root 3 after MEP step 2 and then apparently the molecule got stuck in a local minimum. I performed regular MEP calculations to see how close those roots are. I have figured out that the gap (between root 4 and 3) is around 0.3 eV and 0.2 eV when it reached to the minimum and stopped. Now, I understand why I observed such fast hopping from root 4 to root 3. According to the paper (Journal of Computational Chemistry 2015, 36, 312–320) the default threshold value for energy gap is 0.03 Hartree (0.8 eV). I think this value is very large for my system. Now, I'm wondering whether it's possible to change it in the input file. And what is the appropriate value. I'm not very expert in this regard. Many thanks.

Best,

Last edited by moabe (2018-11-22 11:21:10)

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,085

Re: MEP surface hopping

A MEP ends at a local minimum, that's what a MEP is. If you want it "continue", maybe what you want is to run dynamics.