Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ab initio evaluation of local effective interactions in $\alpha^\prime
  NaV_2O_5$   We will present the numerical evaluation of the hopping and magnetic exchange
integrals for a nearest-neighbor $t-J$ model of the quarter-filled
$\alpha^\prime NaV_2O_5$ 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 $\alpha^\prime NaV_2O_5$ 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.

36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph