[DFTB-Plus-User] electrondynamic and fragmentation

[Cristian Sanchez]

Dear Esi,

> Can I use electrondynamic in dftb+ to study the fragmentation of a molecule under laser pulse?

In principle yes. But: photodissociation most generally involves the crossing of excited and ground state potential energy surfaces mostly through conical intersections. At and near the crossing electron-nuclear wave-function correlation is very important since the nuclear wave-packet necessarily splits and a proper model should take into account this splitting. The Ehrenfest method currently implemented in DFTB+ uses a mean field approach in dealing with the electron-nuclear wave-function description and therefore is, in my experience, not the best suited to approach this particular problem. There are many others for which it works fine though. There are many references in the literature describing this, i.e.:

Horsfield, A. P., Bowler, D. R., Ness, H., Sánchez, C. G., Todorov, T. N., & Fisher, A. J. (2006). The transfer of energy between electrons and ions in solids. Reports on Progress in Physics, 69(4), 1195–1234. http://doi.org/10.1088/0034-4885/69/4/R05

My advice would be to try and see, but to be very careful in the interpretation of the obtained results, in other words: caveat emptor.

All the best,

Cristián


--
Dr. Cristián G. Sánchez

Investigador Independiente
Instituto Interdisciplinario de Ciencias Básicas (ICB)
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)

Profesor Invitado
Facultad de Ciencias Exactas Físicas y Naturales (FCEN)
Universidad Nacional de Cuyo (UNCuyo)

Padre Jorge Contreras 1300, Parque General San Martín
M5502JMA, Mendoza, Argentina

http://www.cgsanchez.net/
cristian.g.sanchez at gmail.com
csanchez at mendoza-conicet.gob.ar
--

> On 3 Aug 2020, at 19:01, esi zamin <esi.zamin at gmail.com> wrote:
> 
> Dear DFTB+ users
> 
> Can I use electrondynamic in dftb+ to study the fragmentation of a molecule under laser pulse?
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