Sturm-Schrödinger equations: Formula for metric

Sturm-Schrodinger equations Hψ = EWψ with H ≠ H † and W≠ = W † ≠ = I are considered, with a weak point of the theory lying in the purely numerical matrix-inversion form of the double-series definition of the necessary metric operator Θ in the physical Hilbert space of states [M Znojil, J. Phys. A: Math. Theor. 41, 215304 (2008]. This shortcoming is removed here via an amended, single-series definition of Θ.