Geometry Optimisation with CASTEP

finite_basis_npoints : n
The number of different cutoff energies at which to evaluate the total energy and work out
basis_de_dloge. The default value is 3.
If an auto finite basis set correction has been performed in the first run of a job it need not be repeated at
the start of the continuation run. The value of basis_de_dloge is given in the .castep file and this can
be included in the .param file along with
finite_basis_corr : manual
Another neat trick is the use of finite basis set corrections to efficiently converge with respect to the basis
set (see this section for more details about convergence with respect to the basis set). The keyword
finite_basis_spacing :
Allows specification of the spacing, in eV, between the finite_basis_npoints:. These are evenly
spaced up to the specified cutoff energy with a default spacing of 5eV. If the user was to specify
finite_basis_npoints : 7
With
finite_basis_spacing : 50
and a cutoff energy of 350eV then singlepoint calculations would be performed at cutoff energies of 50,
100, 150, 200, 250, 300, 350. This would enable very efficient calculations of the convergence of the
total energy with respect to the cutoff energy for a given k-point mesh.
Next: Electronic Minimisation Parameters Up: The .param file Previous: Basis Set Parameters
2005-04-04