By a detailed investigation of the conditions to be satisfied by a mon
o-implicit Runge-Kutta-Nystrom (MIRKN) method in order to be P-stable,
a subset of candidate P-stable MIRKN methods is firstly isolated. The
n it is shown that this subset effectively contains P-stable MIRKN met
hods with an even number of stages. Finally, P-stable MIRKN methods wi
th 2, 4 and 6 stages are constructed explicitly. (C) 1998 IMACS/Elsevi
er Science B.V.