document: The sodium trimer has a long history of theoretical and experimental studies. A pioneering theoretical paper of Martin and Davidson published in 1978 showed that the obtuse isosceles geometry is lower in energy than the linear conformation [6]. Several extended PES scans of Na3 and other alkali trimers followed this initial study, employing DFT [7], complete active space SCF [8], or a configuration interaction approach based on valence bond wave functions [9]. Recently, the applicability of density functional theory (DFT) to JT-distorted systems has also been tested for Na3 [10], and the B-X transition has been revisited as well, applying state-averaged multi-reference configuration interaction with a large active space in order to derive more accurate non-adiabatic coupling terms for an improved interpretation of photoabsorption spectra [11–13].