Posted by Roland Lindh on February 17, 2010 at 08:45:23:
In Reply to: Density Functionals, questions posted by Grigory Shamov on February 05, 2010 at 00:35:58:
Hi Grigory,
thanks for you comments. Here are answers to the best of my ability.
1. This could be implemented but is not at this time. Such gradients would be possible to but would also require some new code since the wave functions is not variational.
2.The gamma_ab would correspond to sqrt(grad(rho(a))*grad(rho(b))). Normally this terms has not contribution. The code was initially implemented for grad(rho) as a parameter, but in practice grad(rho) is only used via gamma. Hence, at some point this was changed. Some parts of the code might not reflect a consistent change to this format (although it should still work).
3. Just email me the stuff together with some documentation of what it is, please. I'll make sure that it is implemented in the development version.
Take care,
-roland