wavefunction91 / IntegratorXX

Reusable DFT Grids for the Masses
BSD 3-Clause "New" or "Revised" License
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NWChem erf partitioning #74

Open susilehtola opened 1 year ago

susilehtola commented 1 year ago

NWChem implements an error function based partitioning described in J. Chem. Phys. 152, 184102 (2020) on page 8

$$ wA({\bf r}) = \prod{B \neq A} \frac 1 2 [ 1 - \text{erf } \mu_{AB}'] $$

where

$$ \mu{AB}' = \frac 1 \alpha \frac {\mu{AB}} { [1 - \mu_{AB}^2]^{n}} $$

and

$$ \mu_{AB} = \frac {\mathbf{r}_A - \mathbf{r}_B} {|\mathbf{r}_A - \mathbf{r}_B|} $$