Abstract
Band-structure calculations of the electronic structure of were performed using the linear muffin-tin orbital method within the local-density approximation (LDA). The results of the calculations were used to determine the parameters of an extended tight-binding model which describes the dispersion of the bands formed by V orbitals and includes explicitly V hopping terms. It has been found that the effective hopping between orbitals of V atoms placed at the opposite ends of consecutive rungs of a ladder is comparable to the hopping along the leg of the ladder, which suppresses the dispersion of the upper pair of V bands. The electronic structure of different models for the charge-ordered low-temperature phase of was studied using the approach. The ground-state energy was calculated and compared for in-line and zigzag charge order in different magnetic configurations. The set of effective exchange constants between magnetic moments was calculated by mapping to the ground-state energy of a localized Heisenberg model.
- Received 19 May 2000
DOI:https://doi.org/10.1103/PhysRevB.62.15538
©2000 American Physical Society