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Anna A. Anisimova

Publications and source records attributed to Anna A. Anisimova.

2 recordsLinked to original sources

Parameterizing DFT+U+V from Hybrid Functionals: A Wannier-Function-Based Approach for Strongly Correlated Materials

We present an approach to parameterize DFT+$U$+$V$ from hybrid-functional calculations using Wannier-function projections. The method constructs a common localized Wannier basis for both semilocal DFT and hybrid-functional calculations, then determines effective on-site ($U$) and intersite ($V$) Hubbard parameters by minimizing the Hamiltonian mismatch within the correlated subspace. This procedure yields interaction parameters that reproduce the hybrid-functional electronic structure at a fraction of the computational cost and allow efficient structural relaxations and further many-body calculations. We validate the workflow on three oxide systems with different electronic characters: MgO (wide-gap insulator), NiO (antiferromagnetic charge-transfer insulator), and V$_2$O$_5$ (d$^0$ transition-metal oxide). In all cases, the mapped DFT+$U$+$V$ parameters reproduce hybrid-functional band gaps, densities of states, and magnetic moments and improve upon semilocal DFT while maintaining computational efficiency.

cond-mat.str-el↗

Chains of magnetic ions in NH$_4^+$-intercalated vanadium pentoxide

We explore the electronic and magnetic properties of NH$_4^+$-intercalated vanadium pentoxide (NH$_4^+$-V$_2$O$_5$), a material that has been identified as a promising cathode for aqueous zinc-ion batteries. Density Functional Theory (DFT) calculations incorporating the Hubbard U correction reveal that NH$_4^+$-V$_2$O$_5$ is an antiferromagnetic insulator with an energy gap of 1.97 eV. The introduction of NH$_4^+$ ions into the V$_2$O$_5$ structure results in significant structural distortions, leading to the formation of magnetic vanadium ions (V$^{4+}$, $3d^1$) and non-magnetic ions (V$^{5+}$, $3d^0$). The magnetic vanadium ions are organized into chains with antiferromagnetic order along the $a$-axis. Our findings indicate that NH$_4^+$-V$_2$O$_5$ exhibits strong electron correlation effects and negligible interchain magnetic interactions, rendering it a promising candidate for a one-dimensional magnetic van der Waals system. This work provides insights into the electronic and magnetic behaviors of NH$_4^+$-V$_2$O$_5$, with implications for its potential applications in energy storage technologies.

cond-mat.str-el↗