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Ab initio evaluation of local effective interactions in $α^\prime NaV_2O_5$

Nicolas Suaud·Marie-Bernadette Lepetit
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Abstract

We will present the numerical evaluation of the hopping and magnetic exchange integrals for a nearest-neighbor $t-J$ model of the quarter-filled $α^\prime NaV_2O_5$ compound. The effective integrals are obtained from valence-spectroscopy {\em ab initio} calculations of embedded crystal fragments (two $VO_5$ pyramids in the different geometries corresponding to the desired parameters). We are using a large configurations interaction (CI) method, where the CI space is specifically optimized to obtain accurate energy differences. We show that the $α^\prime NaV_2O_5$ system can be seen as a two-dimensional asymmetric triangular Heisenberg lattice where the effective sites represent delocalized $V-O-V$ rung entities supporting the magnetic electrons.

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Nicolas Suaud, Marie-Bernadette Lepetit. 2000-07-04. Ab initio evaluation of local effective interactions in $α^\prime NaV_2O_5$. https://doi.org/10.1103/physrevb.62.402

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