Using a combination of Density Functional Theory, mean-field analysis and exact diagonalization calculations we reveal the emergence of a dimerized charge ordered state in TMTTF2-PF6 organic crystal. The interplay between charge and spin order leads to a rich phase diagram. Coexistence of charge ordering with a structural dimerization results in a ferroelectric phase, which has been observed experimentally. The tendency to the dimerization is magnetically driven revealing TMTTF2-PF6 as a multiferroic material.
@article{arxiv.1104.0113,
title = {Magnetism and Charge ordering in TMTTF$_2$-PF$_6$ organic crystals},
author = {Gianluca Giovannetti and Sanjeev Kumar and Jean-Paul Pouget and Massimo Capone},
journal= {arXiv preprint arXiv:1104.0113},
year = {2015}
}