Recurrent variational approach

RECURRENT VARIATIONAL APPROACH APPLIED TO THE ELECTRONIC STRUCTURE OF CONJUGATED POLYMERS... 

Among the technical methods proper to the one dimensional geometry, one may cite the Bethe ansatz [19], the bosonization techniques [18], and, more recently, the Density-Matrix Renormalization Group (DMRG) method (20, 21] and a closely related scheme which is directy considered in this note, the Recurrent Variational Approach (RVA) [22, 21], The two first methods are analytical and the third one is numerical the RVA method is in between. 

To conclude, we have presented in this note the Recurrent Variational Approach and, more specifically, its first application to the electronic structure of conjugated polymers. The ansatz built here (26), shows some nice similarities with the trial state (3) made for the two-leg ladder. 

Recurrent variational approach applied to the electronic structure of conjugated polymers 169... 

Using just-the-faas with data (analysis and reasoning to find and support the root causes of variations, instead of educated guesses or intuition. Experience is a great source of information and is very usefiol in many respects. However, when this knowledge is repeatedly used to fix problems that continue, it represents a bandage approach .The problem is briefly fixed but no permanent controls are put in place to prevent recurrence. 

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