Linear-scaling computation of ground state with time-domain localized-density-matrix method

Recently developed time-domain localized-density-matrix (LDM) method for ca lculating the electronic excited-state properties has been applied to calcu late the electronic ground state. The computational time remains to scale l inearly with the system size. To test the method, we use it to determine th e ground states of polyacetylene oligomers containing up to 20000 carbon at oms. The Pariser-Parr-Pople (PPP) Hamiltonian is employed for the rr electr ons of the systems. Comparison to the conventional diagonalization shows th e high efficiency as well as accuracy of the time-domain LDM method. (C) 19 99 Elsevier Science B.V. All rights reserved.