G ( ψ ) = − ln ( P$_{max}$ ( ψ )) , (2) to which we refer later in this article as the Groverian measure. This measure has three important advantages over other possible measures: (i) It is intrinsically a multipartite measure, rather than an average over bipartite measures for different partitions. (ii) It takes values in the range [0 , ∞ ) , providing a better resolution than measures that are limited to the range [0 , 1) . This is particularly important in the case of highly entangled states with a large number of qubits. (iii) This measure is additive in the sense that if the subsystems A and B are not entangled with each other, then G ( ψ$_{A}$ ⊗ ψ$_{B}$ ) = G ( ψ$_{A}$ ) + G ( ψ$_{B}$ ) . The problem with Groverian-type entanglement measures (and with many other proposed measures), is the difficulty involved in calculating them for general quantum states. The calculation of P$_{max}$ involves finding the product state | ϕ 〉 for which |〈 ϕ | ψ 〉| 2 is maximal. The state | ϕ 〉 is then referred to as the nearest product state. This is a maximization problem in a high-dimensional space. To evaluate the dimensionality of this space, we first consider the two-dimensional Hilbert space H 2 of a single qubit, which has four real parameters. The normalization and the insignificance of the global phase make it possible to express the quantum state of a single qubit in the form with only two real parameters. The first parameter, x$_{m}$ , represents the balance between | 0 〉 and | 1 〉 in the corresponding qubit, and takes values in the range [0 , 1] . When x$_{m}$ = 0 the qubit is in the | 0 〉 state and when x$_{m}$ = 1 it is in the | 1 〉 state. The second parameter is the relative phase θ$_{m}$ . Altogether, finding P$_{max}$ involves maximizing a suitable function in a 2 q - dimensional space. This function typically exhibits a large number of local maxima. For a large number of qubits, this calculation requires significant computational resources, except for some special quantum states for which analytical formulas for P$_{max}$ may be found. So far, a general formula is known only for two-qubit states (using the Schmidt decomposition) and for a very restricted set of highly symmetric states that generalize the GHZ and W states [6]. Recently, some attempts were made to find formulas for the entanglement measure of various three-qubit states [25, 26]. However, so far such formulas were found only for a restricted set of states. For arbitrary states of more than two qubits, the Groverian measure 4 | ϕ$_{m}$ 〉 = √$_{1}$ − x$_{m}$ | 0 〉 + √ x$_{m}$e $^{iθ$_{m}$}$| 1 〉 , (3)