URijkl
| Mind: Available as of VASP.6.5.2. |
This file stores the effectively screened off-centre Coulomb integrals
- [math]\displaystyle{ U_{ijkl}^{\sigma\sigma'} = \int {\rm d}{\bf r}\int {\rm d}{\bf r}' w_{i}^{*\sigma}({\bf r}) w_{j}^{\sigma}({\bf r}) U({\bf r},{\bf r}',\omega) w_{k}^{*\sigma'}({\bf r}'+{\bf R}) w_{l}^{\sigma'}({\bf r}'+{\bf R}) }[/math]
The format is as follows:
# U_ijkl = [ij,R|kl,0] # I J K L RE(V_IJKL) IM(V_IJKL) # R: 1 0.000000 0.000000 0.000000 1 1 1 1 4.3457689208 0.0000000000 2 1 1 1 0.0000021313 0.0000001349 ... # R: 2 0.000000 0.000000 1.000000 1 1 1 1 1.2535567886 0.0000000000 2 1 1 1 0.0324545667 -0.0000455665 ...
The Coulomb integrals are computed and written as a post-processing step using ALGO=2e4wa. The process differs for two types of integrals:
- VRijkl (bare off-centre Coulomb integrals): Always written when requested.
- URijkl: Only written if all WFULLxxxx.tmp files matching the selected k-point grid are present in the working directory.
The basis set for these calculations can be specified using the DMFT_BASIS tag.
Evaluating Coulomb integrals can be computationally intensive, especially when dealing with a large number of basis functions.
| Tip: To improve performance, you can use a coarser sub-grid of the original k-point grid by enabling the LDOWNSAMPLE tag. |