A system of Curvilinear Coordinates defined by

(1) | |||

(2) | |||

(3) |

The Scale Factors are

(4) | |||

(5) | |||

(6) |

The Laplacian is

(7) |

In bispherical coordinates, Laplace's Equation is separable, but the Helmholtz Differential Equation is not.

**References**

Arfken, G. ``Bispherical Coordinates (, , ).'' §2.14 in
*Mathematical Methods for Physicists, 2nd ed.* Orlando, FL: Academic Press, pp. 115-117, 1970.

Morse, P. M. and Feshbach, H. *Methods of Theoretical Physics, Part I.* New York:
McGraw-Hill, pp. 665-666, 1953.

© 1996-9

1999-05-26