https://github.com/deepchem/deepchem/discussions/4703 DFT ideas part

Implement hybrid functionals in the DFT module

Currently the DFT code part of deepchem can only implement pure LDA, GGA, MGGA. I want to ensure it can implement hybrid functional as well

Motivation

The ideas discussed in https://github.com/deepchem/deepchem/discussions/4703 is my primary motivation. By searching for, which problems to work on, I came across this discussion and I have been working on it since then.

Is your feature request related to a problem? Not really a problem, but this is an additional feature.

Additional context

I have added the hybrid functional feature in my code and tested it locally on my machine and matched the energy against PySCF. This is just one part of my code snippet in get_vxc function in hcgto.py file. vxc_linop = SpinParam.apply_fcn( lambda potinfo_: self.get_vxc_from_potinfo(potinfo), potinfo) if self.a_x > 0.0: # this part is my addition k_linop = self.get_exchange(dm) v_exact = SpinParam.apply_fcn(lambda k: self.a_x * k, k_linop) vxc_linop = SpinParam.apply_fcn(lambda vg, vx: vg + vx, vxc_linop, v_exact) return vxc_linop

and this part in get_e_xc function if self.a_x > 0.0: return e_grid + self.a_x * self.get_e_exchange(dm)

return e_grid