On the rovibrational levels of the H₃⁺and H₂D⁺molecules

Abstract

Variationally exact rovibrational levels for the H3 + and H2D+ molecules are calculated using a recently published accurate potential. Vibrational fundamentals are v A 1 = 3191 cm-1 and vE = 2494 (2521·6) cm-1 for H3 + and v 1 = 3000 cm-1, v 2 = 2184 cm-1 and v 3 = 2310 cm-1 for H2D+. For H3 + calculated ground state rotational constants are B 0 = 43·51 (43·57) cm-1, C 0 = 20·59 (20·71) cm-1, DJ 0 = 0·04 (0·05) cm-1, DJ K 0 = -0·07 (-0·10) cm-1 and DK = 0·04 (0·04) cm-1 (where experimental results are given in parenthesis). An attempt is made to stabilize many vibrational states. We thus reassess the results of Carney and Porter. The implications for astrophysics, the interpretation of the infrared spectrum of H3 + near its dissociation limit and the unassigned spectrum of H2D+ are discussed.