title: A new nonsymmetric as (OH)3 species. Comparison with the known C3 species and themochemistry at the HF, DFT(B3LYP), MP2, MP4, and CCSD(T) levels of theory.
abstract: A new nonsymmetric As(OH)(3) species that is more stable than the C(3) structure is found at HF, Density Functional Theory (B3LYP), MP2, MP4 and CCSD(T) levels with the Stuttgart RECP-basis for As and the aug-cc-pvdz/pvtz extended basis sets. Transition state (TS) geometries are close to the C(3) one. Energy differences and interconversion barriers become smaller with increasing inclusion of electronic correlation. However, for MP4 and CCSD(T) descriptions, these differences increase by more than 100% when basis set goes from the AVDZ to AVTZ quality. Zero point energy (ZPE) corrections are essential and have been taken into account at all levels of theory; although this leads to barrier collapse at the B3LYP, MP2, MP4 and CCSD(T) levels, the C(1) isomer remains more stable than the C(3) one. MP2/AVTZ infrared spectra are also given for the C(1) and C(3) isomers as guiding data for future IR studies in the gas phase.
authors.affiliation: Depto. de Física, Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Cuernavaca, Morelos, 62209 México. alex@servm.fc.uaem.mx
authors.forename: Alejandro
authors.initials: A
authors.lastname: Ramírez-Solís
authors.forename: Jorge
authors.initials: J
authors.lastname: Hernandez-Cobos
authors.forename: Cristina
authors.initials: C
authors.lastname: Vargas
mesh_terms: D001151:Arsenic / Q000737:chemistry*; D007536:Isomerism; D008956:Models, Chemical; D015394:Molecular Structure; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D001151:Arsenic