EDAMAME

EDAMAME (Ehrenfest DynAMics on Adaptive MEshes) is a massively parallel FORTRAN95 code written by Daniel Dundas of the ASC.

EDAMAME implements a non-adiabatic quantum molecular dynamics approach that combines a time-dependent density functional theory description of electronic dynamics with a classical description of ionic dynamics (at the Ehrenfest level).

The Kohn-Sham equations of TDDFT are solved in real-space on an adaptive finite difference mesh in 3D. This approach gives a high density of grid points near atomic positions, as illustrated below.

Adaptive Mesh

Illustration of local adaptation around the 12 atoms in the benzene molecule.
The molecule lies in the x-y plane. For clarity only two dimensions are shown.

Using these adaptation techniques both all-electron and pseudo-potential calculations are possible.

Ionization of Benzene by an intense, ultrashort laser pulse
Ionization of benzene by a 5-cycle Ti:sapphire laser pulse. The benzene molecule lies in the plane and the laser pulse is linearly-polarised with the polarization direction horizontal in the plane. The laser wavelength is λ = 780 nm and its peak intensity is I = 4.0x1014 W/cm2. Ionizing electron wavepacket is emitted each half-cycle, in anti-phase to the field, as the laser electric field strength passes through maxima and minima.

Built upon an MPI-based communication suite, EDAMAME can run on a wide range of computer architectures ranging from single processor workstations to large-scale massively parallel processors such as HECToR, the UK national HPC service.


References

D. Dundas, Journal of Chemical Physics,136 194303 (2012)