Equations (32.11) show that the so-called limiting or ‘forbidden’ values Nq
b = 0, 1, Mq – 1, Mq play an important role in calculating the effects of fluctuations on non-uniform surfaces, for which the right-hand sides of expressions (32.11) are not defined . An increase in the number of types of centres t inevitably leads to an increase in the total number of surface sites, which include the ‘forbidden’ numbers of molecules Nq
b = 0, 1, Mq-1, Mq, for large and small fillings of the faces of each type of centre. Their number is Nb = 4t, so with increasing t the total number of boundary values Nb increases.