Magnesium replacement in formaldehyde: Theoretical rovibrational analysis of (X)over-tilde 3B1 MgCH2

A full, anharmonic set of fundamental vibrational frequencies as well as spectrosocpic constants are provided at high-level for (X) over tilde B-3(1) MgCH2 for the first time. The present data are in line with previous computational and Ar-matrix results, but the anharmonic data show that two brightest frequencies, v(4) and v(5), are nearly coincident with one another at 560 cm(-1). Hence, this area is the best spectral region to search for signatures of this molecule. The rotational constants are also provided indicating a near-prolate rotational progression which should aid in microwave/millimeter-wave analysis of this molecule. Magnesium is known to be a significant component of the Earth, and molecules containing it may be more common in the interstellar medium/circumstellar media than previously thought. More spectral characterization of such molecules like MgCH2 should be undertaken, and this work is a step in that direction. (C) 2017 Elsevier Inc. All rights reserved.