Delicate competition between different excitonic orderings in Ta$_2$NiSe$_5$Chatterjee, Banhi (Avtor) Golež, Denis (Avtor) Mravlje, Jernej (Avtor) condensed matter physicssemiconductors2D materialsexcitonic fluctuationsstructural instabilitieselectron correlationsDFT calculationsmean-field theoryWe investigate the energetics of the quasi-one-dimensional layered compound Ta$_2$NiSe$_5$ in the excitonic phase within the six-band model using Hartree–Fock calculations. We calculate energies of states with different kinds of excitonic order and show that they differ by less than meV and depend sensitively on precise values of interchain hopping matrix elements.20252025-12-19 14:29:53Članek v reviji177294UDK: 538.9ISSN pri članku: 2073-4352DOI: 10.3390/cryst15050414COBISS_ID: 262345219sl