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[Licence| Download | New Version Template] adqx_v1_0.tar.gz(935 Kbytes)
Manuscript Title: octopus: a first-principles tool for excited electron-ion dynamics.
Authors: M.A.L. Marques, A. Castro, G.F. Bertsch, A. Rubio
Program title: octopus
Catalogue identifier: ADQX_v1_0
Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 151(2003)60
Programming language: Fortran, C, bison, sh.
Computer: IBM SP3.
Operating system: GNU/Linux, AIX, Tru64 Unix, Irix.
RAM: 50M words
Word size: 32
Keywords: Electronic structure, Linear response, Non-linear response, Non-adiabatic dynamics, Density-functional theory, Time-dependent density-functional theory, Local-density approximation, Generalized-gradient approximation, Real-space methods, Solid state physics, Band structure, Other.
Classification: 7.3, 7.7.

Nature of problem:
Interaction of quantum finite systems with classical electromagnetic fields. The electronic degrees of freedom are described within the Kohn-Sham form of the time-dependent density functional theory, while nuclei are treated as classical point particles.

Solution method:
The electronic wave-functions are discretized in real space using an uniform mesh, and are propagated in real time using nearly unitary propagation schemes. Pseudopotentials are normally used to describe the electron-ion interaction, although model interactions can also be employed. The electromagnetic fields are treated classically either in the length or in the velocity gauge.

Restrictions:
The present version only handles finite systems and classical nuclei. In the near future the code will handle periodic structures.

Unusual features:
The program can be run in either one or three dimensions (we plan to support two dimensions and several categories of periodical systems in future versions). octopus makes use of a very sophisticated, but user-friendly input system.

Additional comments:
Libraries required:
  • BLAS (http://www.netlib.org/blas/),
  • LAPACK (http://www.netlib.org/lapack/),
  • FFTW (http://www.fftw.org/),
  • GSL (http://www.gnu.org/software/gsl/),
  • MPI (http://www-unix.mcs.anl.gov/mpi/).
All of these are available under open-source licences.
The code was parallelized with MPI.

Running time:
For the benzene example (section 7.1), the ground-state calculation took around 15 minutes (in a single processor), while each of the time-evolutions took around 2 days (using 8 processors). These numbers refer to an IBM SP3.