Problems, unfinished work, etc. next up previous contents index
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Subsections

Problems, unfinished work, etc.

Troubleshooting

  1. Diagla occasionally shows bad performance if periodic boundary conditions are used. If you get error messages related to the eigensolver, try Arpack.

  2. Missing symmetry operations: only symmetry operations belonging to the cubic system are tested for existence. That is because the finite grid spacing breaks all other symmetries (for example, the five-fold rotational symmetry in icosahedral molecules). In the Hamiltonian, only some of the present operations are used, and the selection is very stringent. If you feel not all possible symmetry operations are included in the Hamiltonian, try rotating or translating the whole system.

  3. Unrecognized chemical element: Parsec has an internal periodic table (file ptable.f), and it checks for the existence of input elements. If the calculation stops with "unknown element", edit the periodic table.

  4. Current pseudopotential generator does not support asymptotically corrected functionals (LB, CS).

Future implementations

  1. Add k-point sampling in periodic systems.

  2. Allow for a non-orthorhombic periodic cell if periodic boundary conditions are used.


next up previous contents index
Next: Index Up: Parsec 1.1 User's Guide Previous: Post-processing tools   Contents   Index
Murilo Tiago 2005-10-06