title: XZP + 1d and XZP + 1d-DKH basis sets for second-row elements: application to CCSD(T) zero-point vibrational energy and atomization energy calculations.
abstract: Recently, segmented all-electron contracted double, triple, quadruple, quintuple, and sextuple zeta valence plus polarization function (XZP, X = D, T, Q, 5, and 6) basis sets for the elements from H to Ar were constructed for use in conjunction with nonrelativistic and Douglas-Kroll-Hess Hamiltonians. In this work, in order to obtain a better description of some molecular properties, the XZP sets for the second-row elements were augmented with high-exponent d "inner polarization functions," which were optimized in the molecular environment at the second-order Møller-Plesset level. At the coupled cluster level of theory, the inclusion of tight d functions for these elements was found to be essential to improve the agreement between theoretical and experimental zero-point vibrational energies (ZPVEs) and atomization energies. For all of the molecules studied, the ZPVE errors were always smaller than 0.5 %. The atomization energies were also improved by applying corrections due to core/valence correlation and atomic spin-orbit effects. This led to estimates for the atomization energies of various compounds in the gaseous phase. The largest error (1.2 kcal mol(-1)) was found for SiH(4).
authors.affiliation: Departamento de Física, Universidade Federal do Espírito Santo, 29060-900, Vitória, ES, Brazil.
authors.forename: Cesar T
authors.initials: CT
authors.lastname: Campos
authors.forename: Francisco E
authors.initials: FE
authors.lastname: Jorge
authors.forename: Júlia M A
authors.initials: JM
authors.lastname: Alves
mesh_terms: D004583:Electrons; D004602:Elements; D008958:Models, Molecular; D012965:Sodium Chloride / Q000737:chemistry; D013458:Sulfur Dioxide / Q000737:chemistry; D013816:Thermodynamics; D014732:Vibration
chemical_list: D004602:Elements; D013458:Sulfur Dioxide; D012965:Sodium Chloride