This keyword specifies the derivative of total energy with respect to the natural log of the basis cutoff energy. The value is used only if FINITE_BASIS_CORR : 1, which corresponds to manual finite basis set correction. If an automated calculation of this quantity has already been performed, then for the next run on the same system, it is possible to reuse the value via the BASIS_DE_DLOGE keyword. However, this type of correction has very limited applicability since both the system (i.e., the atomic positions and cell parameters) and the calculation parameters have to be exactly the same as in the initial run. In general, the automatic correction mode (FINITE_BASIS_CORR : 2) should be used.
The value of the total energy derivative should always be negative, since the total energy decreases as the size of the basis increases.
CASTEP exits with an error if the value of BASIS_DE_DLOGE is not provided in the parameters file when FINITE_BASIS_CORR : 1.
BASIS_DE_DLOGE : -1.2345 eV
CASTEP keyword glossary
CASTEP parameters keywords