Finite element calculations for the helium atom∗ 1 Introduction

u of the ground state
7
6
5
4
3
u
2
1
0
−1
0
18
16
14
12
10
8
6
4
2
0
−2
0
x 10 −7
x 10 −8
5
r1
5
r1
10
10
15
15
15
10
r2
5
0
18
16
u 14
of
12
the
ground 10
state
8
Figure 1: Wave function of the 1s1s 1 S state(µ = 1).
20
20
15
10
r2
5
0
Figure 2: Wave function of the 1s2s 1 S state(µ = 1). Figure 3: Wave function of the 1s2s 3 S state(µ = 1).
u
6
4
2
0
−2
15
2.5
2
1.5
1
0.5
0
−0.5
−1
−1.5
−2
−2.5
25
x 10 −8
x 10 −5
20
r1
10
r2
15
5
10
r1
5
0
0
0
25
5
20
r1
15
10
r2
5
10 r2
13
15
0