Vibration frequencies using least squares and neural networks for 50 new s and p electron diatomics

Do triatomic molecules echo atomic periodicity?

“…Gas-phase main-group diatomics AB display this periodic behavior dramatically and allow some reasonably precise predictions to be made. [1,2] The properties that have been studied include internuclear separations r e [3], vibration frequencies ω e [3], spring constants k 1 [4], ionization potentials [3], and entire Deslandres tables of band-system Frank-Condon factors [5]. Kong [6] found this same periodicity among contracted internuclear distances of free linear/bent triatomic molecules (Figure 1).…”