title: Electric multipole moments calculation with explicitly correlated coupled-cluster wavefunctions.
abstract: A method of calculation of expectation values of dipole and quadrupole moments with wavefunctions, corresponding to linearly approximated explicitly correlated coupled-cluster singles and doubles [CCSD(F12)] model has been formulated and implemented. As a part of algorithm, explicitly correlated version of Λ equations has also been derived and implemented. Numerical tests, conducted for sets of molecules, show that explicitly correlated results for expectation values of dipole moment are accurate up to 0.01 a.u. already at a double-ζ level compared to those in the complete basis set limit. The corresponding results for quadrupole moments at double-ζ level are accurate up to 0.1 a.u., while for the triple-ζ bases errors do not exceed 0.01 a.u.
authors.affiliation: Laboratory of Molecular Beams, Physical Chemistry Division, Department of Chemistry, Moscow Lomonosov State University, Moscow 119991, Russian Federation.
authors.forename: Denis
authors.initials: D
authors.lastname: Bokhan
authors.affiliation: Laboratory of Molecular Beams, Physical Chemistry Division, Department of Chemistry, Moscow Lomonosov State University, Moscow 119991, Russian Federation.
authors.forename: Dmitrii N
authors.initials: DN
authors.lastname: Trubnikov
authors.affiliation: Quantum Theory Project, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Bartlett