LTWO CENTER
LTWO_CENTER = [logical]
Default: LTWO_CENTER = .FALSE.
Description: LTWO_CENTER calculates off-center Coulomb integrals. When chosen, the system calculates two types of integrals:
- Bare integrals (stored in VRijkl)
- [math]\displaystyle{ V_{ijkl}^{\sigma\sigma'} = \int {\rm d}{\bf r}\int {\rm d}{\bf r}' \frac{w_{i}^{*\sigma}({\bf r}) w_{j}^{\sigma}({\bf r}) w_{k}^{*\sigma'}({\bf r}'+{\bf R}) w_{l}^{\sigma'}({\bf r}'+{\bf R})}{|{\bf r}-{\bf r}'|} }[/math]
- Effectively screened integrals (stored in URijkl)
- [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]
When chosen, cRPA matrix elements in vaspout.h5 can be used with py4vasp to analyze the spatial decay of the Coulomb interaction using the Ohno potential[1]
[math]\displaystyle{ U(R) = \frac{U(R=0)}{\sqrt{\frac{R}\delta + 1}} }[/math]
| Mind: Available as of VASP 6.6.0 |
Related tags and articles
VRijkl, URijkl, LDISENTANGLED, LWEIGHTED, LSCRPA, ALGO