Morate7.8.1 calculations

 Hi CCLers,
 In order to calculate reaction rates for several reactions involving
 polyaromatic compounds, I am using the package MORATE7.8.1 in combination
 with the package MOPAC507MN.  I have to use up to 50 atoms in the calculations.
 However, the program always aborts.  This could be due to an unsufficient memory
 capacity.  The program is able to handle up to 35 atoms.
 Does anyone know what memory capacity is required for the calculation of
 reaction rates for reactions involving up to 50 atoms ?
 With kind regards,