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Correcting Models with Long-Range Electron Interaction Using Generalized Cusp Conditions
Andreas Savin1, Jacek Karwowski2
1Laboratoire de Chimie Théorique, CNRS and Sorbonne University4 Place Jussieu, 75252Paris cedex 05, France.
Abstract:
Sources of energy errors resulting from the replacement of the physical Coulomb interaction by its long-range erfc(μr)/r approximation are explored. It is demonstrated that the results can be dramatically improved and the range of μ giving energies within chemical accuracy limits significantly extended if the generalized cusp conditions are used to represent the wave function at small r. The numerical results for two-electron harmonium are presented and discussed.
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