Direct dynamics studies on the isomerization and H2 elimination reactions of H3PS

Direct ab initio dynamics methods are using to study the H3PS→1trans-H2PSH→2cis-H2PSH, and H3PS→3HPS+H2→4PSH+H2 reactions. The minimum energy paths (MEPs) of the two reaction channels, geometries, and harmonic vibrational frequencies for all stationary points and selected points along the MEPs are calculated using the QCISD/6-311++G(d,p) method. The single-point calculations are carried out by QCISD(T)/6-311++G(2df,2pd). The fitted three-parameter expressions of the calculated CVT/SCT and TST/Eckart rate coefficients in 200-2000 K for reactions (1) and (3) are k1CVT/SCT=2.69×10-42T16.52exp(-9811.9/T)s-1, k1TST/Eckart=1.27×10-31T13.39exp(-12180.6/T)s-1, k3CVT/SCT=8.93×10-20T9.82exp(-20612.1/T)s-1, and k3TST/Eckart=1.31×10-26T11.86exp(-18896.4/T)s-1, respectively.