“…For a hydrogen like atom with a nucleus in the center of a spherically sym metric cavity, almost exact estimates of it energy, polarizability [6,7], oscillator strengths [4,[8][9][10], and other properties [1-3, 9, 11] can be made. For similar problems with a harmonic oscillator in a cavity, see, e.g., [3,[12][13][14][15].…”