With the aid of ab initio calculations, the one-dimensional representations of the ring-puckering vibrations of several four-membered ring molecules have been refined. These one-dimensional models include contributions from MH₂ (M= C, Si, Ge) rocking motions and utilize the computed parameter ω which reflects the relative amounts of ring angle bendings. This model leads to much more accurate determinations of the coordinate dependent kinetic energy expressions $g_{44}$(x) which in turn allow much more accurate calculations of the ring-puckering potential energy functions (PEFs) based on experimental data. The resulting experimental PEFs agree remarkably well with the theoretical functions determined from ab initio calculations. For each molecule spectroscopic data were fit very well utilizing the refined kinetic energy functions and two term PEFs. They were fit even better using three term PEFs including x⁶ terms. The PEFs, barrier heights, and energy minima are presented for each of these molecules and their isotopic species.

借助于从头算，已经精炼了几个四元环分子的起皱振动的一维表示。这些一维模型包括MH ₂（M = C，Si，Ge）摇摆运动的贡献，并利用计算出的参数ω反映了环角弯曲的相对量。该模型可以更精确地确定与坐标有关的动能表达式$G_{44}$（x）反过来可以根据实验数据更准确地计算环起皱势能函数（PEF）。所得的实验PEF与从头算得出的理论功能非常吻合。对于每个分子，利用改进的动能函数和两个项PEF，光谱数据非常吻合。使用包括^6个术语在内的三个术语PEF可以更好地拟合它们。列出了这些分子及其同位素物种的PEF，势垒高度和能量最小值。