In this paper, we study the existence, uniqueness, nondegeneracy and some qualitative properties of positive solutions for the logarithmic Schrödinger equations:Here N ≥ 2 and V ∈ C 2 ((0, +∞)) is allowed to be singular at 0 and repulsive at infinity (i.e., V (r) → −∞ as r → ∞). Under some general assumptions, we show the existence, uniqueness and nondegeneracy of this equation in the radial setting. Specifically, these results apply to singular potentials such as V (r) = α 1 log r + α 2 r α 3 + α 4 with α 1 > 1 − N , α 2 , α 3 ≥ 0 and α 4 ∈ R, which is repulsive for α 1 < 0. We also investigate the connection between some power-law nonlinear Schrödinger equation with a critical frequency potential and the logarithmic-law Schrödinger equation with V (r) = α log r, α > 1 − N , proving convergence of the unique positive radial solution from the power type problem to the logarithmic type problem. Under a further assumption, we also derive the uniqueness and nondegeneracy results in H 1 (R N ) by showing the radial symmetry of solutions.