Deferred correction method

By use of the deferred correction method some of the terms naturally belonging to the coefficient matrix are allocated to the source term because otherwise they may give rise to negative coefficients. The deferred correction method can only be applied when the scheme is being applied as part of an iterative loop structure. The iterative correction of these terms are thus deferred by one iteration, so at the z/-th iteration the source term is evaluated using values known at the end of the previous (z/-l)-th iteration. When convergence is reach, the solution is the same as without the deferred solution but the iterative process... 

The deferred correction method can also be employed to improve the convergence properties of high order schemes, rewriting a high order flux approximation as the sum of a stable low order flux and a higher order correction in the following manner ... 

In terms of the deferred correction method the corresponding coefficients in (12.88) are defined as ... 

If these elements are included in an organic molecule, the choice of computational method can be made based on the organic system with deference to the exceptions listed in this section. If completely inorganic calculations are being performed, use a method that tends to correctly model the property of interest in organic systems. 

There are several methods in use. Their examination is deferred to the next section. Here we remark that during the charging process there is a progressive increase of the dielectric polarization vector P which reaches the correct, or equilibrium, value at the end of the process. 

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