//This calculates the potential energy of an Alavi Hydrogen at a particular centre of mass position and orientation
double CoulombPotential(interfaceStor *interface, H2_orient *lin_mol) {
	
	double potential, q_centre, q_mol, V_ceil;
	VECT zeroVec;
	
	
	
	zeroVec.DIM(3);
	zeroVec.COOR(0) = 0.0;
	zeroVec.COOR(1) = 0.0;
	zeroVec.COOR(2) = 0.0;
	
	q_centre = interface->potential->centreCharge;
	q_mol = interface->potential->molCharge;
	V_ceil = interface->potential->coulombPotentialCeil;
	
	potential = CoulombEng(zeroVec, q_centre, *(lin_mol->CM), q_mol);
	
	//potential =0.0;
	
	if (fabs(potential) > fabs(V_ceil)) {
		potential = V_ceil;
	} 
	
	return potential;
}