A state interaction spin-orbit coupling density matrix renormalization group method
We describe a state interaction spin-orbit (SISO) coupling method using density matrix renormalization group (DMRG) wavefunctions and the spin-orbit mean-field (SOMF) operator. We implement our DMRG-SISO scheme using a spin-adapted algorithm that computes transition density matrices between arbitrary matrix product states. To demonstrate the potential of the DMRG-SISO scheme we present accurate benchmark calculations for the zero-field splitting of the copper and gold atoms, comparing to earlier complete active space self-consistent-field and second-order complete active space perturbation theory results in the same basis. We also compute the effects of spin-orbit coupling on the spin-ladder of the iron-sulfur dimer complex [Fe_2S_2(SCH_3)_4]^(3−), determining the splitting of the lowest quartet and sextet states. We find that the magnitude of the zero-field splitting for the higher quartet and sextet states approaches a significant fraction of the Heisenberg exchange parameter.
© 2016 AIP Publishing. Received 31 March 2016; accepted 26 May 2016; published online 15 June 2016. This work was supported by the US National Science Foundation, through the Award No. NSF:CHE-1265277.
Published - 1_2E4953445.pdf