Hydrogen molecule zero-order approximation

In the zero-order approximation we ignore the electron-electron repulsion, represented by the term proportional to l/ri2. The zero-order electronic Hamiltonian operator is now a sum of two hydrogen-molecule-ion Hamiltonians ... 

In the Born-Oppenheimer approximation the zero-order electronic Hamiltonian operator for diatomic helium consists of four hydrogen-molecule-ion-like (HMIL) Hamiltonian operators ... 

MCH and in H2 at temperatures below 370°C. Toluene desorption was identified as the rate-limiting step. It was found that at low pressures the reaction rate increases with MCH partial pressure, and at higher pressures there is no effect of MCH partial pressure on the reaction rate. This change in apparent order occurs at 1 mmHg MCH partial pressure approximately. On the other hand, it was also reported (15) that the hydrogen partial pressure has no effect on the reaction rate. These reaction orders close to zero for both reactant under practical conditions indicate that the platinum surface active sites are completely covered by adsorbed hydrocarbons (reactant molecules or intermediate compounds). The reaction proceeds, according to the following steps ... 

The value of A/ , may now be computt d. Takuig Aroom temperature. Thus, the value of Ki,- should be of the order of magnitude of unity, i.e., approximately half of the molecules will have the yth hydrogen bond, and about half will not. 

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