content_image/357441.jpg content_image/357440.jpg content_image/357439.jpg content_image/357438.jpg content_image/357437.jpg content_image/357436.jpg
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 , 

<img src='content_image/357441.jpg'>

After a straightforward integration, we find the total photodetachment cross section can be written as a product form 

where 

<img src='content_image/357440.jpg'>

<img src='content_image/357439.jpg'>

<img src='content_image/357438.jpg'>

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 

<img src='content_image/357437.jpg'>

The function I ( S ) also appears in the modulation function for the two-center problem studied previously[36]. 

## III. OSCILLATIONS AND LIMITS OF CROSS SECTIONS 

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 

<img src='content_image/357436.jpg'>

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 

