5.10. gga

DFT functions that are only needed for (meta-)GGA calculations.

Most functions here have been optimized for performance and can be harder to understand than normal. To mitigate this, easier (but slower) implementations have been added as comments.

Functions

calc_Vtau	Calculate the tau-dependent potential contribution for meta-GGAs.
get_grad_field	Calculate the gradient of fields on the grid per spin channel.
get_tau	Calculate the positive-definite kinetic energy densities per spin.
gradient_correction	Calculate the gradient correction for the exchange-correlation potential.