Subroutine package for calculating molecular structures by the paramagnetic-additive method

Abstract

Deriving adequate information on the molecular structure requires a maximally complete and simultaneous incorporation of all the factors influencing the induced NMR shifts. They have devised the LISMIN subroutine package for defining the global minimum in a function of many variables representing the square of the deviation of the theoretically calculated shifts from the observations. The package minimizes the function by optimizing the values of parameters in it. The maximum number of parameters is 150. The values of 55 parameters can be varied simultaneously. During a single calculation, the status of the parameters can be changed from fixed to variable and vice versa, which enables one to find the minimum for 150 variables while ensuring convergence.