An extension of the Weyl limit-point, limit-circle classification for the Sturm-Liouville equation with a complex-valued potential on , where and and are the endpoints regular and singular, respectively, was obtained by A. R. Sims [J. Math. Mech., Vol. 6, 247-285 (1957; Zbl 0077.29201)]. The authors establish an analogue of the Sims theory to the equation
where and are complex-valued, and is a positive weight function. An -function is constructed and a relationship between its properties and the spectrum of corresponding -accretive operators is analysed.