CheMPS2: A free open-source spin-adapted implementation of the density matrix renormalization group for ab initio quantum chemistry

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018) Abstract The density matrix renormalization group (DMRG) has become an indispensable numerical tool to find exact eigenstates of finite-size quantum systems with strong correlation. In the fields of condensed matter, nuclear structure and molecular electronic structure, it has significantly extended the system sizes that can be handled compared to full configuration interaction, without losing numerical accuracy. For quantum chemistry (QC), the most efficient implementations of DMRG require the incorp... Title of program: CheMPS2 Catalogue Id: AESE_v1_0 Nature of problem The many-body Hilbert space grows exponentially with the number of single-particle states. Exact diagonalization solvers can therefore only handle small systems, of up to 18 electrons in 18 orbitals. Interesting active spaces are often significantly larger. Versions of this program held in the CPC repository in Mendeley Data AESE_v1_0; CheMPS2; 10.1016/j.cpc.2014.01.019 AESE_v2_0; CheMPS2; 10.1016/j.cpc.2015.01.00