Lifetime of undiscovered element and its calculation Reading about nuclear models, nuclear physics and the mythical ``stability island'' I just wondered about the next question: 
How can the lifetime of any undiscovered superheavy element be calculated or estimated theoretically? 
Moreover...Does it correspond to a numerical recipe or a theoretical closed approximated formula? Is the lifetime of superheavy atoms the same as that of the superheavy nuclei it has? Any good rereferences about this hard topic? For instance would be welcome! 
Comment: I would also be interested in how could someone calculate (if possible) the lifetime of, e.g., Ubh-310 from first principles with the aid of PC or grid computing...
 A: Transuranic elements are typically unstable with respect to both alpha decay and spontaneous fission.
The log of the half-life for alpha decay varies approximately linearly with $E^{-1/2}$, where $E$ is the energy of the alpha. If you know the binding energies of the parent and daughter nuclei, then you can calculate $E$ from conservation of energy. Provided that you have a decent idea of the spectrum of single-particle energies, the binding energies can be estimated pretty accurately and with minimal computational effort using a technique due to Strutinsky.[Strutinsky 1968]
For spontaneous fission, it's not sufficient to know just the binding energies. In the classical liquid drop model, the nucleus would elongate, form a neck, and eventually undergo scission. This process can be described by some shape parameter $x$ that varies as the shape changes. Quantum-mechanically, you can use the Strutinsky technique to calculate a potential energy $V(x)$, and find a tunneling probability. Although $x$ is not really a good quantum-mechanical coordinate (e.g., you can have $<x|x'>\ne0$ for $x\ne x'$), this all works well enough and gives results that can be compared with theory. There is a conjugate momentum corresponding to $x$, which is not easy to calculate; you need something that plays the role of mass, which is called an inertial parameter, and which nobody really knows how to calculate reliably. Typically one just picks some number for the inertial parameter in order to get agreement with previously measured half-lives.
Strutinsky, Nucl. Phys. A122 (1968) 1. This paper http://arxiv.org/abs/1004.0079 describes a variation on the technique, but also describes the technique itself.
