To get the total photodetachment cross section, we integrate the differential photode- tachment cross section using Eq.(5) and Eq.(7) over θ and φ , After a straightforward integration, we find the total photodetachment cross section can be written as a product form where In the above equations, σ 0 ( E ) is the smooth total photodetachment cross section of H − [3] and A 3 ( kd, θ$_{L}$ ) is a modulation function for the triatomic anion. The function I ( S ) appearing in Eq.(11) is given by The function I ( S ) also appears in the modulation function for the two-center problem studied previously[36]. First we show the cross section obtained by Afaq et al .[38] for the perpendicular config- uration can be obtained from the general formulas. When the laser polarization direction is perpendicular to the direction of the axis, θ$_{L}$ = π $_{2}$. From Eqs.(9)-(12) we immediately have The result in Eq.(13) is identical to that given by Afaq et al. [38]. In Fig.2 we compare the photodetachment cross section in Eq.(13) with the cases θ$_{L}$ = 0 and θ$_{L}$ = π 4 in Eqs.(9)- (12) when d = 4 a 0 . Indeed we do not find any oscillation in the the cross section for θ$_{L}$ = π 2 in agreement with Afaq et al. [38]. But when the direction of laser polarization is 5 III. OSCILLATIONS AND LIMITS OF CROSS SECTIONS σ ( E, d, π 2 ) = σ 0 ( E )[1 + 4[ sin( kd ) ( kd ) 3 − cos( kd ) ( kd ) 2 ] + 4[ sin(2 kd ) (2 kd ) 3 − cos(2 kd ) (2 kd ) 2 ]] . (13) I ( S ) = 3 cos 2 θ$_{L}$ [ sin S S + 3 cos S S 2 − 3 sin S S 3 ] + 3[ sin S S 3 − cos S S 2 ] . (12) A 3 ( kd, θ$_{L}$ ) = 1 + 4 3 I ( kd ) + 2 3 I (2 kd ) . (11) σ 0 ( E ) = $_{16}$√$_{2}$$_{B}$ $^{2}$π$^{2}$E 3 2 3 c ( E$_{b}$ + E ) 3 , (10) σ ( E, d, θ$_{L}$ ) = σ 0 ( E ) A 3 ( kd, θ$_{L}$ ) , (9) σ ( E, d, θ$_{L}$ ) = 2 πE$_{ph}$ c ∫ ( j · ˆ r ) r $^{2}$sin θdθdφ. (8)