Multi-implicit SD-methods for stiff systems of differential equations

The new set of absolutely stable difference schemes for a numerical solution of ODEs stiff systems is submitted. The main feature of the set is the multi-implicit finite differences with the second derivatives of the desired solution. The schemes with 4, 6 and 8 orders of accuracy in detail are considered. The testing results of difference schemes on the Hill's problem and the Kreiss stiff system are shown. The procedure of automatic selection of an integration step with the control of accuracy is submitted. The considerable advantage in efficiency of the high order schemes with the automatic step selection is shown.