title: A Local Pair Natural Orbital-Based Multireference Mukherjee's Coupled Cluster Method.
abstract: This paper reports the development of a local variant of Mukherjee's state-specific multireference coupled cluster method based on the pair natural orbital approach (LPNO-MkCC). The current implementation is restricted to single and double excitations. The performance of the LPNO-MkCCSD method was tested on calculations of naphthyne isomers, tetramethyleneethane, and β-carotene molecules. The results show that 99.7-99.8% of correlation energy was recovered with respect to the MkCC method based on canonical orbitals. Moreover, the errors of relative energies between different isomers or along a potential energy curve (with respect to the canonical method) are below 0.4 kcal/mol, safely within the chemical accuracy. The computational efficiency of our implementation of LPNO-MkCCSD in the ORCA program allows calculation of the β-carotene molecule (96 atoms and 1984 basis functions) on a single CPU core.
authors.affiliation: J. Heyrovský Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic , Dolejškova 3, 18223 Prague 8, Czech Republic.
authors.forename: Ondřej
authors.initials: O
authors.lastname: Demel
authors.affiliation: J. Heyrovský Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic , Dolejškova 3, 18223 Prague 8, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Pittner
authors.affiliation: Max Planck Institute of Chemical Energy Conversion, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Neese