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.