3 Results for As I

The computed oscillator strengths for various transitions from the ground state of As I are presented in Tables 2 and 3. There is not a great deal of experimental and theoretical data available; in fact, there is data only for the resonance transition 4p³(⁴S $^{\circ }_{3/2}$) $\rightarrow$4p²(³P)5s(⁴P_J). For the J=1/2 component of this transition, the presented calculated value, 0.0532, lies inside the range of experimental values, 0.059 $\pm$ 0.008 ([Bengtsson et al. 1992]), and is in reasonable agreement with the experimental values 0.074 ([Andersen et al. 1974]) and 0.0734 ([Lotrian et al. 1980]).

 

Table 3: Oscillator strengths for As I for the transitions 4p³(⁴S $^{\circ }_{3/2}$) $\rightarrow$4p²(³P)ns(⁴P_J), n>5, and 4p³(⁴S $^{\circ }_{3/2}$) $\rightarrow$ 4p²(³P)nd(⁴P_J), n>3, from the present calculations

4p to	J=1/2	J=3/2	J=5/2
6s	0.0075	0.0151	0.0226
7s	0.0027	0.0054	0.0081
8s	0.0013	0.0026	0.0039
9s	0.00072	0.0014	0.0022
4d	0.1981	0.3962	0.5943
5d	0.0551	0.1101	0.1652
6d	0.0234	0.0468	0.0702
7d	0.0123	0.0246	0.0369
8d	0.0072	0.0145	0.0217
9d	0.0050	0.0099	0.0149

 

Table 4: Oscillator strengths, f, for the transitions 4p²(³P₀) $\rightarrow$ 4p(²P$^\circ$)ns(³P $^\circ _{1}$) and 4p²(³P₀) $\rightarrow$ 4p(²P$^\circ$)nd(³P $^\circ _{1}$, ³D $^\circ _{1}$) from As II, from the present calculations, and other calculations

Upper	$\lambda$	f (this	f (other
State	(Å)	calculation)	calculations)
5s	1263.8	0.3547	0.32a, 0.292b, 0.26c
			0.23d, 0.18e
6s		0.0451
7s		0.0150
8s		0.00703
9s		0.00392
4d(3P$^\circ _{1}$)	890.3	0.5166	0.20d
4d(3D$^\circ _{1}$)	1009.5	1.5497	1.4d
5d(3P$^\circ _{1}$)		0.0435
5d(3D$^\circ _{1}$)		0.1306
6d(3P$^\circ _{1}$)		0.0128
6d(3D$^\circ _{1}$)		0.0383
7d(3P$^\circ _{1}$)		0.00568
7d(3D$^\circ _{1}$)		0.0170
8d(3P$^\circ _{1}$)		0.00310
8d(3D$^\circ _{1}$)		0.00930
9d(3P$^\circ _{1}$)		0.00190
9d(3D$^\circ _{1}$)		0.00571

^a

Cardelli et al. (1993): uses the Coulomb approximation with a Hartree-Slater core.

^b

Warner & Kirkpatrick (1969): uses scaled-Thomas-Fermi radial wave functions and intermediate coupling techniques.

^c

Bieron et al. (1991): uses a relativistic configuration interaction approach.

^d

Brage & Leckrone (1995): uses multiconfiguration Hartree-Fock and semiempirical configuration interaction techniques.

^e

Gruzdev (1968): uses the Coulomb approximation and an intermediate coupling scheme.

Calculations have been performed using a variety of techniques. The present value, 0.0532, is in good agreement with the theoretical value 0.0584 ([Verner et al. 1994]) and lies between the theoretical values 0.03 ([Lawrence 1967]) and 0.06 ([Holmgren 1975]). For J=3/2, the present value, 0.1064, lies just inside the experimental range $0.123 \pm 0.017$ ([Bengtsson et al. 1992]), and is in reasonable agreement with the experimental values 0.14 ([Andersen et al. 1974]) and 0.139 ([Lotrian et al. 1980]). The present value is in good agreement with the theoretical values 0.11 ([Holmgren 1975]) and 0.113 ([Verner et al. 1994]). For J=5/2, the present value, 0.1596, is in reasonable agreement with the experimental values 0.21 ([Andersen et al. 1974]) and 0.214 ([Lotrian et al. 1980]), and is in excellent agreement with the theoretical values 0.16 ([Holmgren 1975]) and 0.161 ([Verner et al. 1994]).

In Table 3 we present our computed oscillator strengths for transitions to higher s-states and d-states. Due to the absence of any experimental or theoretical data on these transitions, no comparisons can be made.

 

Table 5: Oscillator strengths, f, for the transitions 4s²4p(²P $^{\circ }_{1/2}$) $\rightarrow$4s²ns(²S_1/2) and 4s²4p(²P $^{\circ }_{1/2}$) $\rightarrow$ 4s²nd(²D_3/2) in As III, from the present calculations, other calculations, andexperiment

Upper	$\lambda$(Å)	f (this	f	f (other
State		calculation)	(experiment)	calculations)
5s	937.3	0.1228	$0.13 \pm 0.02^a$	0.125b, 0.147c
				0.185d
6s	613.9	0.0198		0.0192b
7s		0.00738
8s		0.00367
9s		0.00212
4d	850.0	0.9877	$0.88 \pm 0.15^a$	1.026b, 1.437f
			$1.30 \pm 0.08^e$	1.531d
5d	603.8	0.0797		0.0858b, 0.153d
6d		0.0223
7d		0.00949
8d		0.00500
9d		0.00299

^a

Andersen & Lindgard (1977): uses the beam-foil technique.

^b

Migdalek (1976): uses a relativistic semiempirical approach involving the Dirac equation.

^c

Migdalek (1983): uses a relativistic Hartree-Fock method.

^d

Marcinek & Migdalek (1993): uses a multiconfiguration Hartree-Fock method.

^e

Pinnington et al. (1981): uses the beam-foil technique.

^f

Aashamar et al. (1983): uses multiconfiguration optimized potential model.