method, or the Gear version for stiff equations [1]. These routines work with vector solutions.
A precise method for solving systems of coupled ordinary differential equations of second order in one variable is presented. The In this paper we present an algebraic method of integrating method consists mostly of algebraic manipulations and is very effisystems of coupled differential equations with a regular singular cient on vector computers. The method is applied to the solution point at the origin. The method represents the solution on small of the three-body Schro Β¨dinger equation. Besides giving, in contrast intervals of the independent variable, z, by matrix Taylor series;
to variational methods, uniformly precise expectation values of opon the first interval, at z Ο 0, a modified series in z is used.
erators including the Hamiltonian, the method allows one to study the analytic structure of the wave function. Applications to the He The coefficients of the ODE are expanded in matrix Laurent atom, the muonic helium atom, and the Θdt molecular ion are preseries around z Ο 0. The solution on each interval is obtained via sented. No extended precision intermediate calculations are rerecurrence relations. A small number of powers of z is required.
quired.