Collect. Czech. Chem. Commun.
1985, 50, 1519-1536
https://doi.org/10.1135/cccc19851519
Reduced double-minimum potential curves for XY3 pyramidal molecules
Vladimír Špirkoa, Svatopluk Civišb, Stanislav Berana, Petr Čárskya and Jürgen Fabianc
a The J. Heyrovský Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, 121 38 Prague 2, Czechoslovakia
b Department of Inorganic Chemistry, Charles University, 128 40 Prague 2, Czechoslovakia
c Department of Chemistry, Technical University of Dresden, 8027 Dresden, G.D.R.
Abstract
The reduced potential curve (RPC) method used by Jenc and Pliva for studying the diatomic potentials is adapted for three-parameter studies of the inversional double-minimum potential functions of XY3 pyramidal molecules. Reduced double-minimum potential curves (RDMPC's) of the first, second and third row hydrides (CH3-, NH3, OH3+; SiH3-, PH3, SH3+; GeH3-, AsH3, SeH3+) are constructed using CNDO/2 and ab initio MBPT(2) theoretical potentials. The theoretical RDMPC's corresponding to a group of isoelectronic hydrides coincide to a high degree of approximation, so that they can be represented by a single curve. Furthermore, there is a nearly perfect coincidence between the theoretical RDMPC's of the first row hydrides and the ammonia experimental RDMPC (the only curve known experimentally). To illustrate a practical use of the proposed RPC approach, several approximants to the genuine phosphine potential are constructed (over a wide range of values for the inversion motion coordinate) by combining the available experimental data and the calculated RDMPC's. The resulting potentials exhibit a very close coincidence.
