Quantum similarity superposition algorithm

Bultinck, P., Kuppens, T, Girones, X. and Carbo-Dorca, R. (2003) Quantum similarity superposition algorithm (QSSA) a consistent scheme for molecular alignment and molecular similarity based on quantum chemistry. J. Chem. Inf. Comput. Sci., 43, 1143-1150. 

From a mathematical point of view, we can propose maximization of the MQSM as a function of a set of molecular alignment parameters in such a way as to obtain a superposition procedure with a general scope. Several algorithms aimed directly at maximizing the MQSM have been published. The first example is the MaxiSim algorithm developed by Constans et al. A second one is the quantum similarity superposition algorithm (QSSA) by Bultinck et al. An algorithm developed by Stefanov and Cioslowski is similar to the MaxiSim and QSSA ideas, and it will therefore not be described explicitly because it invokes similar points of view. 

Molecular quantum similarity measures, as formulated in integral (1), are dependent on the relative position of both studied molecules in space. Consequently, a procedure capable of arranging the molecular coordinates needs to be established. Two methodologies have been implemented to deal with this question the maximal similarity rule (MSR) [71], which considers that the optimal orientation corresponds to the one that maximizes the value of integral (1) and the topo-geometrical superposition algorithm... 

Carbo-Dorca R, Besalii E, Mercado LD (2011) Communications on quantum similarity. Part 3 a geometric-quantum similarity molecular superposition algorithm. J Comput Chem 32 582-599... 

In the trapped-ion system, the qubit levels are two electronic states of the trapped charged atom. Using superpositions, states in which the qubit is in 0 and 1, one can process all possible input states at once with a given algorithm (quantum parallelism). The only catch is that once the algorithm terminates, the answer must be read out. Similar to Schrddinger s cat, which, upon looking, is... 

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