Feature: Implementations of Range-Separated Hybrid Functionals

[1041176461]

Range-separated hybrid (RSH) functionals are a class of hybrid functionals that partition the Fock exchange into short-range and long-range components:

To address the divergence issue of the Coulomb potential at $q\to0$, two distinct RSH frameworks have been implemented:

1. Conventional Spencer-Alavi truncated Coulomb potential

   • More efficient in initialization,
   • but suffers from divergence when computing long-range corrected hybrid functionals (e.g., LC-PBE).

2. Massidda’s auxiliary-function-modified Ewald summation scheme

   • Resolves the limitations of the Spencer-Alavi truncation method.

This computational framework serves as the foundation for the upcoming implementation of GW and RT-TDDFT-EXX functionalities.

[dyzheng]

Congratulations on your outstanding work!
From the perspective of long-term code maintenance, I suggest you add sufficient comments to enable other developers to understand the functionality of this part of the code. Unless you promise to respond and maintain all issues related to the code.

[mohanchen]

Hi, you may need to resolve the conflicts, thanks for your efforts! @1041176461

[1041176461]

I moved mixing parameters into "conv_coulomb_pot_k.h" and changed short-range hybrid functionals mixing settings to match with range-separated hybrid functionals. @maki49 @AroundPeking @PeizeLin @Flying-dragon-boxing @JGHan7 Please check whether the current modification will affect your code (see commit 9e9c5e8). Thanks.