1 \documentclass[12pt
]{article
}
6 E & = & E_d + E_
{mbt
} + E_
{ebt
} + E_
{at
} + E_
{aat
} + E_
{bb13
} \\
7 E_d & = &
\sum_{n=
1}^
{3} K_n
[ 1 -
\cos (n
\phi -
\phi_n)
] \\
8 E_
{mbt
} & = & (r_
{jk
} - r_2)
[ A_1
\cos (
\phi) + A_2
\cos (
2\phi) + A_3
\cos (
3\phi)
] \\
9 E_
{ebt
} & = & (r_
{ij
} - r_1)
[ B_1
\cos (
\phi) + B_2
\cos (
2\phi) + B_3
\cos (
3\phi)
] + \\
10 & & (r_
{kl
} - r_3)
[ C_1
\cos (
\phi) + C_2
\cos (
2\phi) + C_3
\cos (
3\phi)
] \\
11 E_
{at
} & = & (
\theta_{ijk
} -
\theta_1)
[ D_1
\cos (
\phi) + D_2
\cos (
2\phi) + D_3
\cos (
3\phi)
] + \\
12 & & (
\theta_{jkl
} -
\theta_2)
[ E_1
\cos (
\phi) + E_2
\cos (
2\phi) + E_3
\cos (
3\phi)
] \\
13 E_
{aat
} & = & M (
\theta_{ijk
} -
\theta_1) (
\theta_{jkl
} -
\theta_2)
\cos (
\phi) \\
14 E_
{bb13
} & = & N (r_
{ij
} - r_1) (r_
{kl
} - r_3)