Calculation of the First and Second terms in heat/gran/conduction equation

Hello every one,

I am trying to modify the code which was written for heat/gran/conduction to change some parameters.

I was able to find the code for the second term for heat conduction equation ( heat transfer coefficient, particles temperature), but I was not able to find the source and header files in which the first term of heat conduction was written (time step, change of temperature with change of time step, specific thermal conductivity and particle mass ).

Could some one please refer me to the codes in which the parameters of the first term were calculated.

Any help would be appreciated. Thanks in advance

Regards,

Luton