Why is my SPC water model calculating a significantly higher energy value?

[edie21]

Hello, I wrote program Monte-Carlo to calculate potential energy of SPC water molecule. But I've got a problem with energy. In all the publications reported value of the energy is 45-48 kJ/mol. However, my program calculate the value of energy significantly higher (50000 KJ/mol). I don't include relative permittivity (epsr=1). I don't know where is the mistake (my model -soft sphere sphere with three charges immersed in the sphere, or my program is wrong). I include file with program written in pascal (object Delphi)

 

[starvis]

Did you check your units ?
Try to calculate the pot. energy without charges and see what you get.

 

[starvis]

The other thing you can try is to fix the distance between both hydrogen atoms.