An approximate wave function expressed in terms of exponential functions, spherical harmonics, etc., with numerical coefficients has been calculated for the ground state of the beryllium atom. Judged ...

It is shown that for wave functions of the form Ψ = Σk Ck exp (-Qk), where Qk is any positive definite quadratic form in the Cartesian co-ordinates of n particles and Ck a constant, all integrals ...

Prolate spheroidal wave functions (PSWFs) and their discrete counterparts – the discrete prolate spheroidal sequences (DPSSs) – have emerged as essential tools in the analysis of band ...